Court Opinion

ID: 9323755
Source: CourtListenerOpinion
Date Created: 2022-12-08 02:03:06.344868+00
Date Added: 2024-06-11T17:14:50.174682
License: Public Domain

Gen. 153]                                                          153

                   CONSTITUTIONAL LAW

SEARCH AND SEIZURE – CANNABIS – WHETHER THE PARTIAL
    LEGALIZATION OF CANNABIS UNDER MARYLAND LAW
    WILL AFFECT THE AUTHORITY OF MARYLAND POLICE
    OFFICERS TO CONDUCT SEARCHES BASED ON THE ODOR
    OF CANNABIS

                       December 1, 2022

The Honorable Bill Ferguson, President of the Senate
The Honorable Adrienne A. Jones, Speaker of the House

      At the November 2022 general election, Maryland voters
ratified an amendment to the Maryland Constitution to allow
individuals who are 21 or older to legally possess and use cannabis
beginning on July 1, 2023, subject to further regulation and
restriction by the General Assembly.1 Because of restrictions
already enacted by the General Assembly that were contingent on
passage of the constitutional amendment, the practical result of that
amendment will be the partial legalization, not the full legalization,
of cannabis for those over 21 years of age. More specifically, that
legislation will, starting July 1, allow an adult over 21 to possess
up to 1.5 ounces of cannabis without penalty. Possession of more
than 1.5 ounces but less than 2.5 ounces will be a civil offense, and
possession of 2.5 ounces or more will remain a crime. The General
Assembly has requested our opinion on “the impact of cannabis
legalization on the authority of police officers to conduct searches
of individuals and vehicles based on detection of the odor of burnt
or unburnt cannabis, including in cases involving suspicion of
possession with intent to distribute cannabis, growing or
manufacturing cannabis or cannabis products, or driving under the
influence of cannabis.” 2022 Md. Laws, ch. 26, § 12.

      Absent action by the General Assembly to impose limits on
police searches beyond what the United States Constitution or the
Maryland Constitution would require, these are questions that the
courts will ultimately have to resolve. All we can do is predict, as
best we can, how the courts will resolve the questions, using the
limited body of existing precedent from the Court of Appeals of

  1
    Effective June 1, 2022, the term “cannabis” replaced all references
to “marijuana” in the Maryland Annotated Code. 2022 Md. Laws, ch.
26, §§ 13, 19. Thus, we use the term “cannabis,” rather than
“marijuana,” throughout this opinion.
154                                                     [107 Op. Att’y

Maryland2 as our most important guide. Under Maryland’s current
statutory scheme, which has decriminalized but not legalized some
possession and use of recreational cannabis and will remain largely
in effect until July 1, 2023, the Court has said that the odor of
cannabis, standing alone, authorizes a police officer to search a
vehicle but does not allow an officer to arrest and search a person.
In transitioning to the impending partial legalization regime, the
most difficult question is whether, once some use and possession
of cannabis becomes legal on July 1, the odor of cannabis
emanating from a vehicle, standing alone, will still authorize a
police officer to search a vehicle, though there are other questions
that we examine as well.

       Based on existing precedent, it is our opinion that, although
not entirely clear, the Court of Appeals is more likely to hold that
the odor of cannabis emanating from a vehicle will still justify a
police officer’s search of that vehicle after July 1, 2023. We realize
it might seem counterintuitive, at first glance, that the odor of a
drug that will often be legal to possess under Maryland law would
justify such a search. But a closer look at the Court’s precedents
suggests that the Court is more likely to reach that conclusion. That
is because, to conduct a search of a vehicle under the Constitution,
an officer needs only probable cause to believe that the vehicle
contains evidence of a crime, not that a person in the vehicle has
committed or is committing a crime. And, even after Maryland
eliminated criminal penalties for the possession and use of some
amount of recreational cannabis in 2014, the Court of Appeals has
still found that the odor of cannabis coming from a vehicle provides
probable cause to believe that the vehicle may contain evidence of
crimes such as possession of a criminal amount of cannabis, driving
under the influence of cannabis, possession of cannabis with the
intent to distribute, and the illegal distribution of cannabis.
Because all those crimes will remain on the books under the new
partial legalization regime (and because probable cause requires
only a fair probability, not a more-than-fifty-percent likelihood,
that evidence of a crime is present in the vehicle), we cannot say
that the Court would depart from its prior reasoning after July 1.
That is especially true given that the General Assembly has not yet

  2
     At the November 2022 election, Maryland voters also ratified an
amendment that will change the name of the Court of Appeals of
Maryland to the Supreme Court of Maryland and will change the name
of the Court of Special Appeals to the Appellate Court of Maryland. But
because the final steps in the process for amending the Constitution have
not yet been completed, see Md. Const., Art. XIV, § 1 (requiring a
proclamation by the Governor), we will continue to refer to these courts
by their soon-to-be obsolete names.
Gen. 153]                                                          155

set up a legal marketplace for the sale of recreational cannabis in
Maryland, which means that cannabis found in a vehicle will
presumably often be evidence of the illegal sale of cannabis, even
if the dealer is not in the vehicle.

      To be clear, however, the odor of cannabis coming from a
vehicle will not, standing alone, authorize a police officer’s search
of the vehicle’s occupants. We also note that the partial
legalization of cannabis calls into question the authority of police
officers to use canines that are trained to detect the odor of cannabis
to establish probable cause to search a vehicle. Under current law,
canine sniffs are ordinarily not considered “searches” under the
Constitution because they can reveal only the presence or absence
of contraband and, thus, do not invade any reasonable expectation
of privacy. But, once the law changes so that only certain amounts
of cannabis will be contraband, the use of a police canine to sniff
for cannabis may itself constitute a search, which would require
probable cause from some other source, rather than serve as the
basis for probable cause.

      Outside of the vehicle context, the odor of cannabis
emanating from an individual, without more, will not justify a
police officer’s arrest and search of that person. After all, even
before the State’s partial legalization scheme has taken effect, the
Court of Appeals has already said that the odor of cannabis, by
itself, does not give an officer probable cause to make an arrest and
conduct a search incident to that arrest. But the odor of cannabis
will likely still permit a police officer to briefly detain the person
to investigate whether they have a criminal amount of cannabis.
And the odor of cannabis will still be a factor that may contribute,
under the totality of the circumstances, to an officer’s authority to
arrest and search a person.
                                 I
                            Background

      For decades, the possession or use of any amount of cannabis
in Maryland was a crime punishable by incarceration and a fine.
See, e.g., Md. Code Ann., Crim. Law (“CL”) § 5-601 (2012 Repl.
Vol.) (criminalizing the possession of a “controlled dangerous
substance”); id. § 5-101(f) (defining “controlled dangerous
substance” to include a drug listed in Schedule I of the Maryland
controlled dangerous substances statute), § 5-402 (d)(1)(vii)
(including cannabis within Schedule I); see also id. § 5-402(a)(3)
(providing that Schedule I under Maryland law consists of each
controlled dangerous substance that the federal government has
156                                                     [107 Op. Att’y

designated a Schedule I controlled dangerous substance); 21 U.S.C.
§ 812, Schedule I (c)(10) (listing “[m]arihuana”—what Maryland
law now refers to as cannabis—as a Schedule I drug under the
federal statute).3

      In 2014, the General Assembly decriminalized—but did not
legalize—the use or possession of less than 10 grams (about 0.35
ounces) of cannabis. 2014 Md. Laws, ch. 158 (codified at CL § 5-
601(c)(2)); Robinson v. State, 451 Md. 94, 96-97 (2017). Under
this law, which is still in effect, the use or possession of less than
10 grams of cannabis is no longer a crime punishable by
incarceration but a civil offense for which an individual may be
fined. CL § 5-601(c)(2).4 The use or possession of 10 grams or
more of cannabis remains a crime, punishable by both incarceration
and a fine. Id.

     Since 2014, the General Assembly has also expanded
Maryland’s medical cannabis program and clarified that cannabis
does not include hemp. As to medical cannabis, the General
Assembly in 2014 authorized licensed dispensaries to provide
medical cannabis to card-carrying patients. 2014 Md. Laws, ch.
256. To accommodate the use of cannabis for medical purposes,
Maryland’s criminal laws now recognize several affirmative
defenses for the use or possession of cannabis for “medical
necessity” or for “palliative relief from [a] debilitating medical
condition.” See CL § 5-601(c)(3)(ii) (providing that, in a
prosecution for criminal use or possession of cannabis, a court must
dismiss the charge upon finding that the person used or possessed
cannabis because of “medical necessity”), § 5-601(c)(3)(iii)(1)
(providing for an affirmative defense when the use or possession
of cannabis is for “therapeutic or palliative relief from [a]
debilitating medical condition”). Section 13-3313(a) of the Health-
General Article also provides that a patient or caregiver of a patient
  3
     Under federal law, a substance is classified as a Schedule I drug if:
“(A) [t]he drug or other substance has a high potential for abuse”;
“(B) [t]he drug or other substance has no currently accepted medical use
in treatment in the United States”; and “(C) [t]here is a lack of accepted
safety for use of the drug or other substance under medical supervision.”
21 U.S.C. § 812(b)(1).
   4
      If the person using or possessing less than 10 grams of cannabis is
under 21, a court must also order the person to attend a drug education
program, refer the person to an assessment for substance abuse disorder,
and, if necessary, refer the person to substance abuse treatment. CL § 5-
601(c)(2)(ii)(4)(A). These additional consequences apply also to the
third or subsequent offense committed by a person who is 21 or older.
CL § 5-601(c)(2)(ii)(4)(B).
Gen. 153]                                                         157

using medical cannabis may not be subject to arrest, prosecution,
or any civil or administrative penalty so long as the person acts in
accordance with the State’s medical cannabis laws.

      As for hemp, the General Assembly in 2015 legalized
industrial hemp, which it defined to mean “the plant Cannabis
sativa L. and any part of such plant, whether growing or not, with
a [THC] concentration that does not exceed 0.3% on a dry weight
basis.” 2015 Md. Laws, ch. 456.5 The law also excluded industrial
hemp from the definition of cannabis (then called “marijuana”). Id.
In 2019, the General Assembly renamed “industrial hemp” to
“hemp” and expanded the definition to include “all derivatives,
extracts, cannabinoids, isomers, acids, salts, and salts of isomers”
of the Cannabis sativa L. plant with a THC concentration that does
not exceed 0.3% on a dry weight basis. 2019 Md. Laws, ch. 228.
Cannabis is still defined to exclude hemp. CL § 5-101(r)(2)(vi).
Federal law also excludes hemp from Schedule I controlled
substances. 21 U.S.C. § 812, Schedule I (c)(17).

      During the 2022 legislative session, the General Assembly
passed two major bills concerning the legalization of recreational
cannabis. The first, House Bill 1, proposed an amendment to the
Maryland Constitution to legalize possession and use of cannabis
under certain conditions. 2022 Md. Laws, ch. 45. The amendment,
approved by voters in Maryland’s November 2022 general
election, provides that an individual who is at least 21 years old
will be able to possess and use cannabis beginning on July 1, 2023,
subject to regulation by the General Assembly.6 Id.

    The second bill, House Bill 837, addresses the limits of the
impending legalization of cannabis and was largely contingent
upon voters’ approval of the constitutional amendment. 2022 Md.
Laws, ch. 26. The legislation specifies that a person who is at least
  5
     THC, the more common name for delta-9-tetrahydrocannabinol, is
a mind-altering chemical found in the cannabis plant. National Inst. on
Drug Abuse, Cannabis (Marijuana), https://nida.nih.gov/research-
topics/cannabis-marijuana (last visited Nov. 30, 2022).
  6
      Under legislation contingent on voters’ approval of the
constitutional amendment, the use or possession of up to 1.5 ounces of
cannabis will become a civil offense from January 1, 2023, through June
30, 2023, the day before the use or possession of that amount will
become legal for individuals who are at least 21 years old. 2022 Md.
Laws, ch. 26, § 3 (amending CL § 5-601), § 15. Effective July 1, 2023,
the use or possession of up to 1.5 ounces of cannabis will be a civil
offense only for those who are younger than 21 years old. 2022 Md.
Laws, ch. 26, § 4 (amending CL § 5-601), § 16.
158                                                       [107 Op. Att’y

21 or older will not be subject to any criminal or civil penalties for
possessing up to 1.5 ounces (about 42.5 grams) of cannabis (the
“personal use amount”).7 2022 Md. Laws, ch. 26, § 4 (amending
CL §§ 5-101, 5-601). The use or possession of the “civil use
amount”—more than 1.5 ounces of cannabis but not more than 2.5
ounces (about 71 grams)8—will be a civil offense, punishable by a
fine but not incarceration. Id. § 4 (amending CL §§ 5-101, 5-601).
The use or possession of more than 2.5 ounces will be a crime. Id.
     Several other existing cannabis-related offenses will remain
subject to criminal or civil penalties under the legislation. For
example, it will remain a crime to drive under the influence of
cannabis,9 to cultivate more than two cannabis plants,10 and to

   7
     The “personal use amount” is alternatively defined as an amount of
concentrated cannabis that does not exceed 12 grams, an amount of
cannabis products containing THC that does not exceed 750 milligrams,
or two or fewer cannabis plants. 2022 Md. Laws, ch. 26, § 4 (amending
CL § 5-101). Concentrated cannabis products are made by extracting
substances from the plant into a form with a much higher THC
concentration than the flower. L. Cinnamon Bidwell et al., Exploring
Cannabis Concentrates on the Legal Market: User Profiles, Product
Strength, and Health-Related Outcomes, 8 Addictive Behavs. Reps. 102,
102 (2018).
   8
       The civil use amount is defined alternatively as an amount of
concentrated cannabis that exceeds 12 grams but does not exceed 20
grams, or an amount of cannabis products containing THC that exceeds
750 milligrams but does not exceed 1,250 milligrams. 2022 Md. Laws,
ch. 26, § 4 (amending CL § 5-101).
    9
      Md. Code Ann. Transp. § 21-902(c) (providing that a person “may
not drive or attempt to drive any vehicle while so far impaired by any
drug, any combination of drugs, or a combination of one or more drugs
and alcohol that the person cannot drive a vehicle safely”), § 21-902(d)
(providing that a person “may not drive or attempt to drive any vehicle
while the person is impaired by any controlled dangerous substance . . .
if the person is not entitled to use the controlled dangerous substance
under the laws of this State”); see also 2022 Md. Laws, ch. 26, § 4
(amending CL § 5-601(d) to specify that legalization of the personal use
amount of cannabis and decriminalization of the civil use amount “may
not be construed to affect the laws relating to . . . operating a vehicle or
vessel while under the influence of or while impaired by a controlled
dangerous substance”).
    10
       2022 Md. Laws, ch. 26, § 4 (adding new CL § 5-601.2). Only
individuals 21 and older will be allowed to grow cannabis, and plants
may not be cultivated in a location where the plants are subject to public
view. Id. Violation of this law will be a misdemeanor subject to a three-
Gen. 153]                                                             159

distribute cannabis or possess cannabis with the intent to distribute
it.11 The General Assembly has not yet enacted legislation
establishing a legal marketplace for recreational cannabis, so—at
least at first—the sale of cannabis will remain illegal even when
the use and possession of cannabis is not. It will be a civil offense
to smoke cannabis in public,12 to smoke it on mass transit and in
other indoor spaces regulated under the Clean Indoor Air Act,13 and

year prison sentence and/or a fine of up to $5,000. Id. Licensed medical
cannabis growers will not be limited to growing only two plants. See
Maryland       Medical     Cannabis      Commission,      Growers     FAQ,
https://mmcc.maryland.gov/Pages/growers.aspx (last visited Nov. 30,
2022) (noting that regulations do not specify the maximum number of plants
that a licensed grower may cultivate); see also Md. Code Ann., Health-Gen.
§ 13-3306(h) (providing that a licensed grower may not be penalized for
cultivating plants for a medical cannabis processor or dispensary).
   11
        The law currently prohibits the possession of “a controlled
dangerous substance in sufficient quantity reasonably to indicate under
all circumstances an intent to distribute or dispense [the] controlled
dangerous substance.” CL § 5-602(2). Licensed medical cannabis
dispensaries may not be penalized for distributing “medical cannabis,
products containing medical cannabis, related supplies, or educational
materials for use by a qualifying patient, a caregiver, or an academic
research representative.” Md. Code Ann., Health-Gen. § 13-3307(g).
The law criminalizing possession with intent to distribute will change on
January 1, 2023, to specify that possession of the civil use amount or the
personal use amount of cannabis, “without other evidence of an intent to
distribute or dispense,” does not constitute possession with the intent to
distribute cannabis. 2022 Md. Laws, ch. 26, § 5 (adding CL § 5-602(b)),
§ 18 (specifying that this change will take effect January 1, 2023). This
will apparently codify a principle that Maryland courts have long
recognized, i.e., that “no specific quantity of drugs has been delineated
that distinguishes between a quantity from which one can infer [an intent
for personal use as opposed to an intent to distribute] and a quantity from
which one cannot make such an inference.” Collins v. State, 89 Md.
App. 273, 279 (1991). Beginning July 1, 2023, individuals who are at
least 21 years old will be allowed to share with others who are at least
21 years old the personal use amount of cannabis, without any civil or
criminal penalties. 2022 Md. Laws, ch. 26, § 4 (adding CL § 5-602(c)),
§ 16 (specifying that this change will take effect July 1, 2023).
  12
      2022 Md. Laws, ch. 26, § 4 (providing that, under CL § 5-601(c)(4),
smoking cannabis in public will be a civil offense punishable by a fine
of up to $250 for a first finding of guilt, and a fine of up to $500 for a
second or subsequent finding of guilt).
   13
      2022 Md. Laws, ch. 26, § 5 (amending Md. Code Ann., Health-
Gen. §§ 24-501 through 24-504 to clarify that a person may not smoke
cannabis in an indoor space where tobacco smoking is already unlawful:
160                                                       [107 Op. Att’y

to smoke cannabis in a passenger area of a motor vehicle on a
highway.14
     Regardless of the impending legalization of some possession
and use of cannabis under Maryland law, the drug will remain a
controlled substance that is illegal to possess or distribute under
federal law. See 21 U.S.C. § 812 (listing marijuana as a Schedule
I controlled substance), § 841 (imposing criminal penalties for the
manufacture, distribution, and possession with intent to distribute
a controlled substance), § 844(a) (imposing criminal penalties for
simple possession of a controlled substance).15

                                  II
                                Analysis

      The question before us is what impact the impending
legalization of certain amounts of cannabis under Maryland law
will have on the authority of police officers to conduct searches of
vehicles and individuals based on the odor of cannabis. Police
searches are subject to the Fourth Amendment to the U.S.
Constitution, which protects against unreasonable searches and
seizures.16 We thus begin our analysis by examining the Fourth

an indoor area open to the public, an indoor place in which meetings are
open to the public under the Open Meetings Act, mass transit, or an
indoor place of employment).
   14
      2022 Md. Laws, ch. 26, § 6 (amending CL § 10-125 to prohibit an
occupant of a motor vehicle from smoking cannabis in a passenger area
of a motor vehicle on a highway and amending Md. Code Ann., Transp.
(“TR”) § 21-903 to prohibit a driver from smoking or consuming
cannabis in a passenger area of a motor vehicle on a highway). Violation
of CL § 10-125 will be a civil offense, subject to a fine not to exceed $25.
CL § 10-126(g). Violating TR § 21-903 may result in the issuance of a
traffic citation. TR § 26-201.
   15
       On October 6, 2022, President Joe Biden pardoned all people
convicted of cannabis possession under federal law and said that his
administration would review whether cannabis should remain a Schedule
I drug. White House, Statement from President Biden on Marijuana
Reform, (Oct. 6, 2022), https://www.whitehouse.gov/briefing-
room/statements-releases/2022/10/06/statement-from-president-biden-
on-marijuana-reform/.
   16
      Maryland’s constitution has an analogous provision, Article 26 of
the Declaration of Rights. But because Article 26 has historically been
read in pari materia with the Fourth Amendment, see, e.g., King v. State,
434 Md. 472, 482 (2013), we focus our analysis on the federal
Gen. 153]                                                             161

Amendment principles that govern police searches generally. We
then consider how Maryland’s appellate courts have applied these
principles in cases involving the odor of cannabis—first, under the
State statutory scheme that, until 2014, criminalized the possession
of any amount of cannabis, and second, under the current State
statutory scheme, which has decriminalized the possession and use
of less than 10 grams of cannabis and will remain in effect, with
few changes,17 until July 1, 2023.
A.   Constitutional Principles that Apply to Police Searches
     Generally

      The Fourth Amendment, which protects against
“unreasonable governmental intrusions,” Winston v. Lee, 470 U.S.
753, 767 (1985), generally requires a police officer to obtain a
warrant before conducting a search, e.g., Riley v. California, 573
U.S. 373, 382 (2014). A judge shall issue a warrant only if the
officer has demonstrated probable cause for the search, i.e., “a fair
probability that contraband or evidence of a crime will be found in
a particular place.” Illinois v. Gates, 462 U.S. 213, 238 (1983).
“Nevertheless, because the ultimate touchstone of the Fourth
Amendment is ‘reasonableness,’ the warrant requirement is subject
to certain exceptions.” Brigham City v. Stuart, 547 U.S. 398, 403
(2006). Two of those exceptions are relevant to our analysis: the

constitutional provision. The United States Supreme Court is, of course,
“the final arbiter of the meaning and application of the [federal]
Constitution,” R & T Constr. Co. v. Judge, 323 Md. 514, 520 (1991),
including the Fourth Amendment. But the Supreme Court has yet to
consider a Fourth Amendment challenge to a search based on the odor
of cannabis in a state that has decriminalized or legalized some use and
possession of cannabis. Moreover, Maryland’s courts would be the first
to address a Fourth Amendment challenge in a State prosecution under
the impending legalization scheme. We thus focus our attention on how
Maryland’s appellate courts have applied the Fourth Amendment in
cases involving the odor of cannabis.
   17
      As noted above, no possession or use of recreational cannabis will
be legal until July 1, 2023, but the amount that a person may possess
subject only to civil penalties (as opposed to criminal penalties) will
increase from 10 grams to 1.5 ounces beginning January 1, 2023, and
continuing through June 30, 2023. 2022 Md. Laws, ch. 26, § 3
(amending CL § 5-601). The law criminalizing possession with intent to
distribute will also change on January 1, 2023, to specify that possession
of the civil use amount or the personal use amount of cannabis, “without
other evidence of an intent to distribute or dispense,” does not constitute
possession with the intent to distribute cannabis. Id. §§ 5, 18.
162                                                 [107 Op. Att’y

search incident to arrest exception, and the automobile exception
(also known as the Carroll doctrine).
      1.   Search Incident to Arrest Exception

      Under the search incident to arrest exception, police may
lawfully search a person pursuant to a warrantless arrest if the
police have probable cause to believe that the person “has
committed a felony or is committing a felony or misdemeanor in
the presence of the police.” Pacheco v. State, 465 Md. 311, 321-
22 (2019) (citing Maryland v. Pringle, 540 U.S. 366, 369-70
(2003)). Probable cause is “a fluid concept,” Gates, 462 U.S. at
232, “incapable of precise definition or quantification into
percentages because it deals with probabilities and depends on the
totality of the circumstances,” Pringle, 540 U.S. at 371. The
standard takes into account “the factual and practical
considerations of everyday life,” id. at 370 (quoting Gates, 462
U.S. at 231), requiring less evidence “than would justify conviction
but more evidence than that which would arouse a mere suspicion,”
Doering v. State, 313 Md. 384, 403 (1988). Thus, to justify an
arrest, a police officer must be able to point to “specific and
articulable facts,” which, taken together, “would lead a reasonably
cautious person to believe” that a crime had been or was being
committed by the person arrested. State v. Wallace, 372 Md. 137,
148 (2002). But probable cause is “not a high bar,” State v.
Johnson, 458 Md. 519, 535 (2018) (quoting District of Columbia
v. Wesby, 138 S. Ct. 577, 586 (2018)), requiring less than proof by
the preponderance of the evidence, Freeman v. State, 249 Md. App.
269, 301-02 (2021).
      The justifications for the search incident to arrest exception
are to preserve evidence and to protect police officers by ensuring
that the arrested person does not have weapons. See, e.g., Arizona
v. Gant, 556 U.S. 332, 338 (2009). Under this exception, police
may search the arrestee’s person and the area within the arrested
person’s immediate control. Id. at 339.

      2.   Automobile Exception

     Another exception to the warrant requirement is the
automobile exception, also known as the Carroll doctrine. The
U.S. Supreme Court first articulated this exception in Carroll v.
United States, 267 U.S. 132 (1925), a Prohibition era case in which
police had probable cause to believe that a car they observed
driving on a road contained illegal liquor. Officers stopped and
searched the vehicle, discovered and seized illegal liquor, and
Gen. 153]                                                           163

arrested the occupants. Id. In upholding the warrantless search and
seizure, the Carroll Court reasoned that “a ‘necessary difference’
exists between searching ‘a store, dwelling house or other
structure’ and searching ‘a ship, motor boat, wagon or automobile’
because a ‘vehicle can be quickly moved out of the locality or
jurisdiction in which the warrant must be sought.’” Collins v.
Virginia, 138 S. Ct. 1663, 1669 (2018) (quoting Carroll, 267 U.S.
at 153). Thus, under the Carroll doctrine, police may conduct a
warrantless search of “an automobile and the containers within it
where they have probable cause to believe contraband or evidence
[of a crime] is contained.” California v. Acevedo, 500 U.S. 565,
580 (1991).18 The justifications for this exception are the “ready
mobility” and “pervasive and continuing governmental regulation”
of vehicles, Collins, 138 S. Ct. at 1669-70, which has reduced
individuals’ expectation of privacy in automobiles, Pennsylvania
v. Labron, 518 U.S. 938, 940 (1996).

      The automobile exception “requires the same ‘quantum of
evidence’”—probable cause—as the search incident to arrest
exception, but each exception “requires a showing of probabilities
as to somewhat different facts and circumstances.” Pacheco, 465
Md. at 324-25 (quoting 2 Wayne R. LaFave, Search and Seizure:
A Treatise on the Fourth Amendment § 3.1(b), at 7 (5th ed. 2012)).
Whereas the search incident to arrest exception requires probable
cause to believe that the arrested person has committed a crime, see
supra Part II.A.1, the Carroll doctrine only requires probable cause
to believe that the vehicle contains contraband or evidence of a
crime, Florida v. Harris, 568 U.S. 237, 243 (2013). When police
have the requisite probable cause, they may search “every part of
the vehicle and its contents that may conceal the object of the
search.” Wyoming v. Houghton, 526 U.S. 295, 301 (1999)
(emphasis omitted) (quoting United States v. Ross, 456 U.S. 798,
825 (1982)). But “the scope of the automobile exception extends
no further than the automobile itself,” Collins, 138 S. Ct. at 1671,
and probable cause to search a vehicle does not automatically
provide probable cause to search an occupant of the vehicle, State
v. Wallace, 372 Md. 137, 144 (2002).

  18
     “Although typically described as the automobile exception to the
Fourth Amendment warrant requirement, the Carroll exception also
applies to searches of other vehicles.” Lewis v. State, 470 Md. 1, 20 n.6
(2020); see also Carroll, 267 U.S. at 153 (characterizing “ship[s], motor
boat[s], wagon[s], [and] automobile[s]” as “vehicle[s] [that] can be
quickly moved”); California v. Carney, 471 U.S. 386, 393 n.2 (1985)
(“With few exceptions, the courts have not hesitated to apply the vehicle
exception to vehicles other than automobiles.”).
164                                                     [107 Op. Att’y

       3.   Techniques That a Police Officer May Use to Develop
            Probable Cause
     When an officer lacks probable cause to believe that a person
has committed a crime or that a vehicle contains contraband or
evidence of a crime, the officer may investigate further, employing
techniques that fall short of an arrest or a search under the Fourth
Amendment.
            i.    Terry Stops

      If an officer reasonably suspects that a person is involved in
criminal activity but lacks probable cause to make an arrest, the
officer may nonetheless briefly detain the person, whether the
person is on foot or in a vehicle, to investigate. See, e.g., Kansas
v. Glover, 140 S. Ct. 1183, 1187 (2020); Navarette v. California,
572 U.S. 393, 396-97 (2014). This brief investigatory detention,
commonly known as a Terry stop,19 is “considered less intrusive
than a formal custodial arrest,” Wilson v. State, 409 Md. 415, 440
(2009), and, thus, “requires a less demanding level of suspicion
than probable cause,” Trott v. State, 473 Md. 245, 255 (2021). That
less demanding standard is known as “reasonable suspicion.”

     As with probable cause, reasonable suspicion “takes into
account ‘the totality of the circumstances—the whole picture.’”
Navarette, 572 U.S. at 397 (quoting United States v. Cortez, 449
U.S. 411, 417 (1981)). But while “a mere hunch does not create
reasonable suspicion,” the standard requires “considerably less
than proof of wrongdoing by a preponderance of the evidence and
obviously less than is necessary for probable cause.” Id. The
“reasonable suspicion” standard is less demanding in another way
too. As the Supreme Court has explained:
            Reasonable suspicion is a less demanding
            standard than probable cause not only in the
            sense that reasonable suspicion can be
            established with information that is different
            in quantity or content than that required to
            establish probable cause, but also in the sense
            that reasonable suspicion can arise from
            information that is less reliable than that
            required to show probable cause.

  19
     It was in Terry v. Ohio, 392 U.S. 1, 20-22 (1968), that the Supreme
Court first recognized that an officer may briefly detain someone that the
officer reasonably suspects of committing a crime.
Gen. 153]                                                        165

Alabama v. White, 496 U.S. 325, 330 (1990). When an officer has
reasonable suspicion, the officer may detain the person “only . . .
as long as it takes [the] police officer to confirm or dispel [their]
suspicions.” Swift v. State, 393 Md. 139, 150 (2006); see also
Hiibel v. Sixth Jud. Dist. Ct. of Nevada, 542 U.S. 177, 185 (2004)
(noting that reasonable suspicion “permits the officer to stop the
person for a brief time and take additional steps to investigate
further”).
          ii.    Dog Sniffs

      One way that police commonly confirm or dispel suspicions
of criminal activity (especially during traffic stops) is by using a
dog specially trained to detect the presence of contraband,
including illegal drugs. See, e.g., Wilkes v. State, 364 Md. 554, 565
(2001) (involving a police dog trained to alert to cocaine, heroin,
cannabis, and hashish); Emory v. State, 101 Md. App. 585, 635
(1994) (involving a certified cannabis-sniffing dog). “A dog’s
sense of smell is somewhere between 100,000 and one million
times stronger than a human’s sense of smell.” Melanie
Reid, Goodbye Marijuana Schedule I-Welcome to a Post-
Legalization World, 18 Ohio St. J. Crim. L. 169, 183 (2020). One
might expect, therefore, that use of a police canine to detect drugs
could rise to the level of a search under the Fourth Amendment,
given that it is a special technique that effectively enhances an
officer’s senses beyond ordinary human capacity. Cf. Kyllo v.
United States, 533 U.S. 27, 29-30, 34-35, 40 (2001) (holding that
police officers conducted a search when, from their vehicle parked
on a public street, they used a thermal-imaging device to detect
infrared radiation emanating from a house).

     But, in cases decided before the widespread legalization of
cannabis in many states, the Supreme Court has said that a dog sniff
is generally not “a ‘search’ within the meaning of the Fourth
Amendment.” United States v. Place, 462 U.S. 696, 707 (1983).
The Court’s rationale for that conclusion has been that a “search”
generally occurs only when a government inspection “intrude[s]
upon a legitimate expectation of privacy,” Illinois v. Andreas, 463
U.S. 765, 771 (1983), and a trained dog’s “sniff discloses only the
presence or absence of . . . contraband,” Place, 462 U.S. at 707, in
which an individual has no legitimate privacy interest, Illinois v.
Caballes, 543 U.S. 405, 408 (2005). Indeed, “dog sniffs are unique
in their narrow yes/no determination of the presence of
narcotic[s].” Fitzgerald v. State, 384 Md. 484, 501 (2004); accord
166                                                      [107 Op. Att’y

Place, 462 U.S. at 707 (recognizing that “the canine sniff is sui
generis”).20
      In the pre-legalization context, therefore, the Supreme Court
has held that a dog sniff of a vehicle during a traffic stop is
ordinarily not a search subject to the Fourth Amendment, Caballes,
543 U.S. at 409-10, even though police officers’ use of other sense-
enhancing techniques may sometimes constitute a search, see, e.g.,
Kyllo, 533 U.S. at 29-30. In distinguishing between dog sniffs and
the use of some other techniques that have been found to be
searches under the Fourth Amendment, a key consideration is
whether the technique at issue might reveal the presence of
noncontraband items. See, e.g., Caballes, 543 U.S. at 409-10
(pointing out that “[c]ritical to th[e] [Kyllo] decision was the fact
that the device was capable of detecting lawful activity—in that
case, intimate details in a home”—whereas “[a] dog sniff
conducted during a concededly lawful traffic stop . . . reveals no
information other than the location of a substance that no individual
has any right to possess”); Fitzgerald v. State, 153 Md. App. 601,
684-85 (2003) (contrasting the “limited and binary nature” of a dog
sniff, which reveals only “the presence or absence of contraband
drugs,” with the use of heat-sensing technology in Kyllo, which
“detected . . . unusual amounts of heat . . . generated inside the
home, a phenomenon that is not itself criminal and could well have
had a non-criminal explanation”), aff’d, 384 Md. 484 (2004).
Because trained police dogs have historically been able to detect
only the presence or absence of contraband, the Supreme Court has
said that dog sniffs are generally not searches under the Fourth
Amendment.21

  20
      An officer’s detection of the odor of cannabis using the officer’s
nose, unaided by the use of a specially trained dog, is clearly not a
“search” under the Fourth Amendment, so long as the officer is “lawfully
present” at the place where the officer smells the odor. 1 Wayne R.
LaFave, Search and Seizure: A Treatise on the Fourth Amendment,
§ 2.2(a) (6th ed. 2020). Under “what might be called the ‘plain smell’
rule,” “no search in a Fourth Amendment sense has occurred,” because
no one has a reasonable expectation of privacy in “odors emanating from
private premises, from a vehicle, or from some personal effects nearby”
and detectable by “lawfully positioned agents ‘with inquisitive nostrils.’”
Id. (quoting United States v. Johnston, 497 F.2d 397, 398 (9th Cir. 1974)).
   21
      An exception is when police use a canine to sniff the front door of
a home, an act that violates “the traditional property-based understanding
of the Fourth Amendment,” which prohibits warrantless intrusions into
a home or the area immediately adjacent without the permission of the
homeowner. Florida v. Jardines, 569 U.S. 1, 6, 11 (2013). A dog sniff
Gen. 153]                                                              167

          iii.    Frisks

       In addition to briefly detaining someone if the officer has
reasonable suspicion that the person is engaged in criminal activity,
an officer may conduct a frisk of the person for weapons if the
officer has reasonable suspicion that the person stopped is armed
and dangerous. E.g., Arizona v. Johnson, 555 U.S. 323, 326-27
(2009). The officer must be able to articulate specific facts,
particularized to the person stopped, that reasonably indicate that
the person has a weapon and is presently dangerous. E.g., Ybarra
v. Illinois, 444 U.S. 85, 93-94 (1979). The purpose of the frisk is
“not to discover evidence of crime, but to allow the officer to
pursue [their] investigation without fear of violence.” Adams v.
Williams, 407 U.S. 143, 146 (1972). Thus, an officer need not
establish probable cause before frisking someone the officer
reasonably suspects is armed and dangerous. Because the purpose
of a Terry frisk is to detect the presence of a dangerous weapon, the
scope is limited to patting down a detainee’s outer clothing.
Lockard v. State, 247 Md. App. 90, 105 (2020). This “pat-down”
is sufficient to discover whether the person has a gun, knife, or
other dangerous instrument. Id.

     4.     Summary

     To summarize the constitutional principles that ordinarily
apply in cases involving government searches and seizures, a
police officer generally must obtain a warrant before conducting a
search. But an officer need not obtain a warrant before searching
a person if the officer has a lawful reason to arrest that person.
Likewise, an officer need not obtain a warrant before searching a
vehicle if the officer has probable cause that the vehicle contains
contraband or evidence of a crime. If an officer lacks probable
cause to arrest someone or search a vehicle, the officer may

during a traffic stop on a public roadway does not implicate this property-
based theory and does not violate the Fourth Amendment so long as the
officer has a lawful reason to conduct the traffic stop and the officer does
not prolong the stop simply to allow a canine to arrive and sniff the
vehicle. Once the purpose of “an ordinary traffic stop” “has been
fulfilled, the continued detention of the car and the occupants amounts
to a second detention.” Ferris v. State, 355 Md. 356, 372 (1999). “Thus,
once the underlying basis for the initial traffic stop has concluded, a
police-driver encounter which implicates the Fourth Amendment is
constitutionally permissible only if either (1) the driver consents to the
continuing intrusion or (2) the officer has, at a minimum, a reasonable,
articulable suspicion that criminal activity is afoot” and the canine sniff
would confirm or dispel that suspicion. Id.
168                                                   [107 Op. Att’y

nonetheless briefly detain a person or vehicle, provided the officer
has reasonable suspicion that criminal activity is afoot. During
such a stop, the officer may use a police-trained dog to sniff for
contraband. The officer may also frisk a person if the officer
reasonably suspects that the person is armed and dangerous.
   We turn now to how courts have applied these Fourth
Amendment principles in cases involving the odor of cannabis.
B.    Police Officers’ Authority, Before the Decriminalization of
      Small Amounts of Cannabis, to Conduct Searches Based on
      the Odor of Cannabis

     Before 2014, when the possession or use of any amount of
cannabis was a crime under Maryland law, the odor of cannabis
provided police a lawful basis to search both individuals and
vehicles. See, e.g., McGurk v. State, 201 Md. App. 23, 52 (2011)
(addressing the search of a person incident to arrest); Wilson v.
State, 174 Md. App. 434, 454-55 (2007) (addressing the search of
a vehicle). This was true whether it was an officer who detected
the odor of cannabis, see, e.g., State v. Harding, 166 Md. App. 230,
236 (2005), or a police dog trained to alert to the presence of illegal
drugs, see, e.g., Gadson v. State, 341 Md. 1, 8 (1995).

     As to individuals, the odor of cannabis provided probable
cause to believe that cannabis was present; thus, if an officer could
“localize its source to a person, the officer ha[d] probable cause to
believe that the person ha[d] committed or [was] committing the
crime of possession of [cannabis].” McGurk, 201 Md. App. at 52
(emphasis omitted) (quoting United States v. Humphries, 372 F.3d
653, 659 (4th Cir. 2004)). The probable cause, in turn, authorized
the officer to arrest that person and search them incident to arrest.
See In re D.D., 479 Md. 206, 224 (2022) (recognizing that “the
odor of [cannabis] particularized to a person provided probable
cause for an arrest” before 2014); Pacheco, 465 Md. at 323
(explaining the search incident to arrest exception).

     As to vehicles, the odor of cannabis emanating from an
automobile provided police probable cause to believe that cannabis
was present somewhere in that automobile. Wilson, 174 Md. App.
at 454. Thus, the odor authorized an officer to search the entire
vehicle. Id. at 455 & n.7; see also United States v. Ross, 456 U.S.
798, 824-25 (1982) (“If probable cause justifies the search of a
lawfully stopped vehicle, it justifies the search of every part of the
Gen. 153]                                                             169

vehicle and its contents that may conceal the object of the
search.”).22
      Probable cause to search a vehicle, however, did not
necessarily establish probable cause to search each of the vehicle’s
occupants. Rather, the Court of Appeals said that, “while [an] alert
[to a car] by a drug dog trained to detect contraband[]
undisputedly[] gave the police probable cause to believe there was
contraband somewhere in the car or on the person of someone in
the car, the canine sniff of the vehicle alone did not amount to
probable cause to then search each of the passengers.” State v.
Wallace, 372 Md. 137, 155-56 (2002). Wallace involved a traffic
stop, during which a police dog alerted to the presence of illegal
drugs in the car. Id. at 141. Police removed the three occupants
from the vehicle and searched them. Id. at 142. The Wallace Court
held that the search of the backseat passenger was illegal because
“there was no probable cause for the officer, at that point in time
on the night in question,” to believe that this particular passenger
had illegal drugs. Id. at 157. The Court elaborated:

            Without additional facts that would tend to
            establish    [the    backseat     passenger’s]
            knowledge and dominion or control over the
            contraband before his search, the K-9 sniff of
            the car was insufficient to establish probable
            cause for a search of a non-owner, non-driver
            for possession. Merely sitting in the backseat
            of a car did not amount, in this case, to
            probable cause specific to [the backseat

  22
      Wilson involved the odor of burnt cannabis. 174 Md. App. at 438.
According to some out-of-state courts, the odor of burnt cannabis
indicates drug use but not drug trafficking, justifying a search of only a
vehicle’s passenger compartment but not the trunk; in these courts’ view,
only the odor of raw (i.e., unburnt) cannabis indicates drug trafficking,
justifying a search of a vehicle’s trunk. Id. at 446-54 (collecting cases).
The Wilson Court rejected this “burnt-raw” distinction, concluding that
it would not be “unreasonable for an officer to believe that the odor of
burnt [cannabis] indicate[d] current possession of unsmoked [cannabis]
somewhere inside of the vehicle, including the trunk.” Id. at 454-55; see
also id. at 456 (“eliminat[ing] the need to distinguish between burnt,
burning, or raw [cannabis]” when determining whether probable cause
exists to search a vehicle). Consistent with the Wilson Court’s
conclusion, the Court of Appeals has said that “[t]he automobile doctrine
permits the search of ‘every part of the vehicle and its contents that may
conceal the object of the search.’” Pacheco, 465 Md. at 322 (quoting
Wyoming v. Houghton, 526 U.S. 295, 301 (1999)).
170                                                      [107 Op. Att’y

              passenger] to search and subsequently arrest
              him.
Id. at 156.23 The Court suggested, however, that the outcome might
have been different if the defendant had been the driver or owner
of the vehicle, id. at 156-57, and, four years later, the Court of
Special Appeals stated that a canine’s alert to illegal drugs in a
vehicle with a driver and one other occupant provided “probable
cause to arrest, at the very least, the driver,” who was “a person
with a more significant connection to the car” than a mere
passenger. State v. Ofori, 170 Md. App. 211, 229, 233 (2006).

      In sum, when the possession or use of any amount of cannabis
was criminal under Maryland law, police could lawfully conduct a
search incident to arrest of an individual who smelled of cannabis.
If the smell of cannabis came from a vehicle, police could search
the entire vehicle and its contents. But the smell of cannabis
coming from a vehicle did not authorize police to search an
occupant of the vehicle unless additional facts connected that
particular occupant to the cannabis.

C.        Police Officers’ Authority, Under the Current Statutory
          Scheme, to Conduct Searches Based on the Odor of
          Cannabis

      Under Maryland’s current statutory scheme—which has
removed the criminal penalties for possession of less than 10 grams
of cannabis but has not legalized it—the odor of cannabis, standing
alone, still provides a police officer justification to search a vehicle,
but it no longer authorizes the search of an individual (though an
officer may briefly detain a person who smells of cannabis to
investigate further). See Robinson v. State, 451 Md. 94, 99 (2017)
(holding that the odor of cannabis emanating from a vehicle
provides a police officer justification to search that vehicle); Lewis
v. State, 470 Md. 1, 10 (2020) (holding that the odor of cannabis
emanating from a person alone does not provide probable cause for
a police officer to arrest and search that person); In re D.D., 479
Md. 206, 215, 217 (2022) (holding that the odor of cannabis on a

     23
      The Wallace Court suggested that police could have established the
requisite link had “the K-9 . . . sniffed [the passenger], and specifically
alerted to [him], before the officer searched him,” or “[i]f the officers
simply had [the dog] sniff each of the passengers of the car prior to
searching them,” in which case “probable cause might have existed to
search any of the passengers who positively re-alerted the canine to
contraband.” Id. at 156.
Gen. 153]                                                          171

person authorizes a police officer to conduct a brief investigatory
detention).
       1.   Searches of Vehicles

      In Robinson v. State, the Court of Appeals for the first time
considered the impact of decriminalization on a police officer’s
authority to conduct a search based on the odor of cannabis. That
decision involved three different defendants, each of whom had
been arrested following a search of an automobile based on an
officer’s detection of a strong odor of “fresh” (i.e., unburnt)
cannabis coming from the vehicle. Robinson, 451 Md. at 99-106.
Challenging these searches, the defendants argued that the odor of
cannabis no longer provided probable cause to search a vehicle,
because an officer could not tell, from odor alone, whether the car
contained a criminal amount of cannabis or a non-criminal amount
of less than 10 grams. Id. at 106-07.

       The Court in Robinson rejected the defendants’ argument,
holding that a police officer still has probable cause to search a
vehicle when the officer detects an odor of cannabis emanating
from the vehicle. Id. at 99. Although the Court acknowledged that
“it is effectively impossible for law enforcement officers to identify
a quantity of [cannabis] based on odor alone,” id. at 130, the Court
noted that possession of less than 10 grams of cannabis, while no
longer criminal, is still illegal, and, thus, “any amount” of cannabis
“remains contraband,” id. at 99.24 The odor of cannabis, then,
“gives rise to probable cause to believe that the vehicle contains
contraband,” id., and the automobile exception authorizes a police
officer to search a vehicle based on probable cause that it contains
contraband, id. at 109.

      The Court went even further, however, holding that, “separate
from the odor of [cannabis] providing probable cause to believe
that a vehicle contains contraband, the odor of [cannabis] provides
probable cause to believe that a vehicle contains evidence of a
crime.” Id. at 133 (emphasis added). Although this part of the
analysis was limited to just one paragraph in a long opinion, the

  24
      Although none of the defendants claimed that they possessed or
used cannabis for medical reasons, Robinson, 451 Md. at 97 n.2, the
Court acknowledged that qualifying patients and their caregivers who
comply with the State’s medical cannabis laws may not be subject to
arrest, prosecution, or any civil or administrative penalty for the
possession of cannabis, id. at 136 (discussing Md. Code Ann., Health-
Gen. § 13-3313(a)). Nonetheless, the Court repeatedly said that cannabis
“in any amount” remains contraband. Id. at 99, 125, 126, 129, 130, 137.
172                                                  [107 Op. Att’y

Court reasoned that “[t]he odor of [cannabis] emanating from a
vehicle may be just as indicative of crimes such as the possession
of more than ten grams of [cannabis], possession of [cannabis] with
the intent to distribute, or the operation of a vehicle under the
influence of a controlled dangerous substance, as it is of possession
of less than ten grams of [cannabis].” Id. at 133-34. Thus, the
Court concluded, an officer who detects the odor of cannabis
emanating from a vehicle has probable cause to search that vehicle
based on the reasonable belief that the vehicle contains evidence of
a crime such as possession of 10 grams or more of cannabis,
distribution of cannabis, or driving under the influence of a
controlled dangerous substance. Id.

      2.   Searches of a Vehicle’s Occupants

       In a series of cases after Robinson, the Court of Appeals
clarified that justification to search a vehicle does not necessarily
establish justification to search or pat down individuals inside that
vehicle. In one case, decided just two months after Robinson, the
Court of Appeals held that, while the odor of cannabis emanating
from a vehicle authorizes an officer to search that vehicle, the
officer needs more than the odor of cannabis to justify frisking the
occupants of that vehicle. Norman v State, 452 Md. 373, 379
(2017). As we noted above, see supra Part II.A.3.iii, a frisk must
be supported by reasonable suspicion that the person is armed and
dangerous. In Norman, an officer stopped a car with a broken
taillight and “detected a strong odor of fresh [cannabis] emanating
from the vehicle’s passenger compartment.” 452 Md. at 379-80.
The officer told the vehicle’s three occupants to get out of the car
so that he could search it for cannabis; the officer then frisked the
occupants to look for weapons and found, in one passenger’s front
pocket, a bag of cannabis. Id. at 380. In challenging the frisk, the
passenger argued that the officer lacked reasonable suspicion,
based solely on the odor of cannabis, that any of the vehicle’s
occupants were armed and dangerous. Id. at 384-85.

      The Court held that the “odor of [cannabis] . . . emanating
from a vehicle with multiple occupants does not,” standing alone,
“give rise to reasonable articulable suspicion that the vehicle’s
occupants are armed and dangerous and subject to frisk.” Id. at
412. Instead, to justify frisking an occupant of the vehicle, an
officer must have “an additional circumstance or circumstances”
indicating that the occupant is armed and dangerous. Id. at 411. In
reaching this conclusion, the Court emphasized its prior holding in
Wallace that the odor of drugs emanating from a vehicle, without
more, does not provide probable cause to search the occupants of a
Gen. 153]                                                          173

vehicle. Id. at 399. While acknowledging that “[a] frisk is different
from a search of a person,” id. at 388, the Court reasoned that both
types of seizures “involve applications of a defendant’s Fourth
Amendment right[] ‘to be secure in their person[ ], . . . against
unreasonable searches,’” a right that “can be violated by either an
unreasonable search or an unreasonable frisk.” Id. at 413 (quoting
U.S. Const. amend. IV). Whether an officer searches a person or
frisks them, the reasonableness of that action depends “on the
circumstances—or the lack of circumstances—that involve the
[person]” searched or frisked. Id. In short, “a law enforcement
officer cannot reasonably infer that a particular occupant of a
vehicle is armed and dangerous just because an odor of [cannabis]
indicates that [cannabis] may be somewhere in the vehicle.” Id. at
425; see also In re D.D., 479 Md. at 228 (“[W]hile the smell of
[cannabis] can justify a quick pat-down of a vehicle’s occupants if
combined with some other pertinent circumstance(s), the odor, in
and of itself, is insufficient to give rise to reasonable suspicion that
a specific individual within the vehicle is armed and dangerous.”).

      In Pacheco, the Court of Appeals revisited the issue of
whether officers may arrest and search a vehicle’s occupants based
on the odor of cannabis. 465 Md. at 330. The Court there reiterated
that “the same facts and circumstances that justify a search of an
automobile do not necessarily justify an arrest and search incident
thereto.” Id. at 333. In Pacheco, two officers approached a vehicle
with its windows down, smelled burnt cannabis, and spotted a joint
in the center console. Id. at 318. One of the officers knew
immediately that the joint contained less than 10 grams of cannabis.
Id. Nonetheless, the officers ordered the driver, who was the sole
occupant, out of the vehicle and searched him, finding cocaine in
one of his front pockets. Id. The officers then searched the vehicle
and found a cannabis stem and two packets of rolling papers. Id.
The officers took the driver to a police station, where they issued
him a citation for possessing less than 10 grams of cannabis and
charged him with possession of cocaine with intent to distribute.
Id.

      In court, the driver did not challenge the search of the vehicle
but argued that police had no authority to search his person. Id. at
318, 330. The Court of Appeals agreed, concluding that the
officers lacked probable cause to arrest (and, thus, search) the
driver based only on “their detection of ‘fresh burnt’ [cannabis]
emanating from the vehicle and the joint they observed in the center
console.” Id. at 332. Although courts will consider “the experience
and special knowledge of police officers,” id. (quoting Longshore
v. State, 399 Md. 486, 534 (2007)), the police in Pacheco did not
174                                                     [107 Op. Att’y

point to any evidence indicating that, “in their experience and
training[,] the possession of one joint . . . supported an inference
that [the driver] also possessed roughly nine and a half more grams
of [cannabis] on his person,” id. at 332-33. And “[n]othing in the
record suggest[ed] . . . that [the driver] intended to distribute
[cannabis] or was operating the vehicle while under the influence
of [cannabis].” Id. at 332 n.7.25

       3.   Searches of Individuals Outside the Vehicle Context

      In 2020, the Court of Appeals for the first time considered the
impact of decriminalization on an officer’s authority to search a
person, outside the vehicle context, based on the odor of cannabis.
Lewis v. State, 470 Md. 1 (2020). The Court in that case held that
“the odor of [cannabis], without more” no longer “provide[s] law
enforcement officers with the requisite probable cause to arrest and
perform a warrantless search of that person incident to arrest.” Id.
at 10. The Court reasoned that “police officers must have probable
cause to believe a person possesses a criminal amount of [cannabis]
in order to arrest that person and conduct a search incident thereto.”
Id. at 23. But, the Court explained, “[t]he odor of [cannabis] alone
is not indicative of the quantity (if any) of [cannabis] in someone’s
possession,” and, thus, does not indicate that a person has
committed a felony or a misdemeanor (as opposed to a civil
infraction or no infraction at all). Id.

      Importantly, the Court in Lewis did not back away from its
reasoning in Robinson that “the odor of [cannabis] emanating from
a vehicle provides probable cause to believe that the vehicle
contains evidence of a crime.” Lewis, 470 Md. at 25 (quoting
Robinson, 451 Md. at 134) (emphasis added). But the Court
clarified that Robinson was limited to the vehicle context. In
explaining why the odor of cannabis provides probable cause to
search a vehicle but not to arrest a person, the Court in Lewis
contrasted the “diminished expectation of privacy one enjoys in
[their] vehicle” with the “heightened expectation of privacy

  25
     In a concurring opinion, Judge McDonald (joined by Judge Watts),
said that the majority opinion “should not be read to preclude a
conclusion that an officer has probable cause for arrest when the officer
comes upon an individual alone and awake in the driver’s seat of a
vehicle with a [cannabis] joint at hand and the pungent odor of [cannabis]
in the air.” Pacheco, 465 Md. at 337 (McDonald, J., concurring). But
to justify an arrest and search of that driver, an officer must be able to
point to other specific facts indicating that the driver has committed the
crime of driving while impaired by cannabis. Id.
Gen. 153]                                                            175

enjoyed in one’s person.” Lewis, 470 Md. at 26. In particular, the
Court explained:
            Arresting and searching a person, without a
            warrant and based exclusively on the odor of
            [cannabis] on that person’s body or breath, is
            unreasonable and does violence to the
            fundamental privacy expectation in one’s
            body; the same concerns do not attend the
            search of a vehicle.

Id. Thus, “more than the odor of [cannabis] is required for probable
cause to arrest a person and conduct a search incident thereto.” Id.
at 17.

      The odor of cannabis does, however, permit a police officer
to briefly detain a person and investigate further. In a case decided
earlier this year, the Court of Appeals concluded that, “[e]ven
following partial decriminalization, the odor of [cannabis] on a
person provides reasonable suspicion to conduct a brief
investigatory detention to attempt to determine whether the person
has committed a criminal offense.” In re D.D., 479 Md. at 249.
That case involved the stop and frisk of D.D., a fifteen-year-old
boy, whom police encountered in an apartment building when
responding to a complaint about the odor of cannabis. Id. at 216.
The officers encountered D.D. and four friends, all smelling of
cannabis, and ordered them to sit down. Id.26

      In upholding this stop, the Court of Appeals emphasized that
a stop requires only reasonable suspicion that criminal activity is
afoot, a standard “less stringent” than the probable cause required
to make an arrest. Id. at 230. Thus, “a particular circumstance or
set of circumstances” may “fall short of probable cause” but
“satisfy the reasonable suspicion standard.” Id. at 231. The Court
concluded that this is “precisely the case with respect to the odor
of [cannabis].” Id. According to the Court, “partial de-
criminalization has reduced the level of certainty associated with
the odor of [cannabis] on a person from probable cause that the
person has committed a crime to reasonable suspicion that the
person has committed a crime or is in the process of committing a
  26
     The Court recounted other facts surrounding the encounter as well,
such as the fact that no one in the group would tell the officers where
they lived, that all were wearing “baggy clothes,” and that the officers
found D.D. in particular “to be evasive.” Id. at 216, 218. But the
majority treated the case as one where the stop was justified by the smell
of cannabis alone. Id. at 241 n.10.
176                                                  [107 Op. Att’y

crime.” Id. at 232. “Put another way, . . . the officers [here] could
not have arrested D.D. or any of the members of the group based
solely on the odor of [cannabis], but that does not mean the
officers’ suspicion that one or more of the group might possess at
least 10 grams of the drug—based on odor alone—was
unreasonable.” Id. at 235-36.

      The Court rejected D.D.’s argument that, “[b]ecause the odor
of [cannabis] alone is not indicative of criminal activity and an
officer must have evidence of a crime in order to conduct an
investigatory stop, it necessarily follows that the odor of [cannabis]
alone does not provide reasonable suspicion to conduct a Terry
stop.” Id. at 224. In doing so, the Court emphasized that neither
probable cause nor reasonable suspicion requires police “to rule out
a suspect’s innocent explanation for suspicious facts.” Id. at 231
(quoting District of Columbia v. Wesby, 138 S. Ct. 577, 588
(2018)). And the Court further reasoned that, even though “there
are many wholly innocent reasons why someone might smell of
[cannabis],” “decriminalization has not rendered the odor of
[cannabis] free of all criminal suspicion . . . because the use or
possession of 10 grams or more of [cannabis] remains a criminal
offense in Maryland.” Id. at 231-32, 235; see also Robinson, 451
Md. at 133-34. In the Court’s view, “[t]here can be no real dispute
that the odor of [cannabis] still provides evidence of a crime . . .
even if it may not rise to the level of probable cause in every
situation.” In re D.D., 479 Md. at 235.
      That the odor of cannabis would justify a stop but not
authorize an arrest also “makes sense,” the Court observed, “given
the differing levels of intrusiveness of the two Fourth Amendment
events” and the balance of interests involved. Id. at 232. While
“[a]n arrest is the ‘most intrusive encounter’ that a police officer
has with a citizen,” id. at 232-33 (quoting Swift v. State, 393 Md.
139, 150 (2006)), an investigatory detention is “limited in duration
and purpose and can only last as long as it takes a police officer to
confirm or to dispel his suspicions,” id. at 233 (quoting Swift, 393
Md. at 150). “Being stopped for a short amount of time so that an
officer can ask a few questions does not do the same ‘violence to
the fundamental privacy expectation in one’s body’ that being
placed in handcuffs and physically searched does.” Id. at 236.
Ultimately, in the Court’s view, “[t]he public interest in
investigating and prosecuting criminal offenses, balanced against
an individual’s freedom of movement and reasonable expectation
of privacy in their person,” justifies “a brief investigatory
detention” based on the odor of cannabis, but not an arrest. Id. at
233. “Indeed,” the Court observed, “it would be peculiar if the odor
Gen. 153]                                                            177

of [cannabis] was sufficient to meet the higher standard of probable
cause needed to search a vehicle, but insufficient to meet the lower
standard of reasonable suspicion needed to briefly stop a person on
the street.” Id. at 236.

      The Court further opined “that accepting D.D.’s argument
could significantly hamper the legitimate investigation of criminal
activity in Maryland.” Id. at 238. The Court noted that “[a]n
officer who lacks probable cause to arrest is not required ‘to simply
shrug his shoulders and allow a crime to occur or a criminal to
escape.’” Id. (quoting Adams v. Williams, 407 U.S. 143, 145
(1972)). But if reasonable suspicion required an officer to rule out
all innocent explanations of suspicious facts, an officer would not
be able to question someone with the butt of a handgun protruding
from their waistband (because some residents may lawfully carry a
firearm), or detain the driver of a car with potentially excessive
window tinting (because “inspection of a tinted window cannot
definitively tell whether the tint exceeds the legal limit”). Id. at
236-37. As to the odor of cannabis, the Court acknowledged that:

            [w]hen a police officer smells [cannabis] on
            someone, it is certainly the case that the
            person may possess less than 10 grams of
            [cannabis] or they may possess no [cannabis]
            at all. But it also is possible that the person is
            presently in possession of 10 or more grams
            of [cannabis]. Under D.D.’s reasoning, police
            officers would be powerless to conduct a brief
            investigatory detention to try to determine
            which category the person is in. That is not
            what the Fourth Amendment requires. To the
            contrary, the odor of [cannabis] permits an
            officer to briefly detain an individual to
            investigate whether that person has committed
            a criminal offense.

Id. at 238.27

  27
      The Court further concluded that, based on the totality of the
circumstances, police had reasonable suspicion to frisk D.D. for a
weapon. In re D.D., 479 Md. at 243-44. Although the odor of cannabis
was one factor, the police also pointed to “the group’s ‘evasive body
language,’ and the fact that there were ‘five of them in baggy clothes’ in
a place ‘where they could run out the door.’” Id. “These circumstances,”
the Court concluded, “viewed collectively, would lead a reasonably
prudent law enforcement officer to suspect that D.D. was armed and
dangerous.” Id.
178                                                     [107 Op. Att’y

      Under the current decriminalization scheme, then, the odor of
cannabis emanating from a vehicle authorizes a police officer to
search that vehicle, whether it is the officer or a specially trained
dog who has detected the odor. The smell of cannabis in a vehicle
standing alone does not, however, authorize a search of the
vehicle’s occupants. And the smell of cannabis emanating from a
person, by itself, is no longer probable cause sufficient to justify an
arrest and search incident to arrest.28 But the odor of cannabis
coming from a person does provide sufficient reasonable
articulable suspicion to permit the officer to briefly detain that
person to investigate further, even without any other indication of
criminal activity.

D.        Police Officers’ Likely Authority to Conduct Searches
          Based on the Odor of Cannabis Once Some Use and
          Possession of Cannabis Becomes Legal

      Finally, we come to the question that the General Assembly
has asked us to answer: whether the legalization of the possession
of up to 1.5 ounces of cannabis will affect the authority of police
officers under the Fourth Amendment to conduct searches based on
the odor of cannabis.

      Before offering our opinion, we pause for a moment to
address the role, if any, of the federal regulation of cannabis. More
specifically, does the fact that possession of any cannabis remains
a crime under federal law provide probable cause for a state’s
officers to search vehicles or individuals, regardless of the status of
cannabis under that state’s law? See, e.g., Kevin Cole, Probable
Cause to Believe What? Partial Marijuana Legalization and the
Role of State Law in Federal Constitutional Doctrine, 54 No. 2
Crim. L. Bull. Art 1 (Spring 2018). There appears to be some
uncertainty about whether federal law offers a basis for state law
enforcement officers to conduct a search based on the odor of
cannabis in a state that has legalized or decriminalized its
possession. See Orin S. Kerr, Cross-Enforcement of the Fourth
Amendment, 132 Harv. L. Rev. 471, 475 (2018); compare
Commonwealth v. Craan, 13 N.E.3d 569, 579 (Mass. 2014)
(holding that, when state law “expressly has decriminalized certain
conduct, there is no extant joint investigation, and the Federal
government has indicated that it will not prosecute certain conduct,
the fact that such conduct is technically subject to a Federal
     28
     That does not mean, however, that the odor of cannabis could not
be one of several factors that establishes probable cause, which, of
course, depends on the totality of the circumstances. See, e.g., Pringle,
540 U.S. at 371.
Gen. 153]                                                          179

prohibition does not provide an independent justification for a
warrantless search”), with United States v. Sanders, 248 F. Supp.
3d 339, 347 (D.R.I. 2017) (finding that the odor of cannabis
contributed to an officer’s reasonable suspicion because,
“regardless of what the R.I. General Assembly has declared” by
decriminalizing the possession of less than one ounce of the drug,
“possession of [cannabis] is still unlawful under federal law”).

      The Maryland Court of Appeals has not addressed this precise
question. More than twenty-five years ago, in a case involving
handgun permitting laws, the Court of Appeals said that “state and
local law enforcement officials may appropriately enforce federal
law.” Department of Pub. Safety v. Berg, 342 Md. 126, 139 (1996).
The Court thus concluded that State Police could deny a handgun
permit to an applicant whose criminal history made him ineligible,
under federal law, to purchase a gun. Id. at 131-32, 139. But, as
far as we can tell, the Court has never decided whether it is
appropriate for a State police officer to rely on federal law to
establish probable cause for an arrest or a search.

      That said, we think the Court of Appeals might have implicitly
decided the issue as applied to searches based on the odor of
cannabis.29 In Robinson, in which the Court held that the odor of
cannabis coming from a vehicle authorizes an officer to search that
vehicle, the Court noted that “[p]ossession of [cannabis] in any
amount . . . remains a crime under federal law.” 451 Md. at 97 n.1
(citing 21 U.S.C. § 844(a)). But the Court did not expressly rely
on this fact to support its holding, nor did the Court mention the
federal law in subsequent cases considering the effect of
Maryland’s decriminalization scheme. In fact, the Court later held
in Lewis that the Fourth Amendment did not permit officers to
arrest an individual (or conduct a search incident to arrest) based
solely on the odor of cannabis. While the Court did not expressly
consider in Lewis whether federal law might provide grounds for
the arrest, we assume that the Court did not forget that possession
of cannabis remains illegal under federal law. We thus infer that,
by holding in Lewis that the odor of cannabis on a person no longer
authorizes an arrest and search of that person, the Court implicitly
decided that a police officer in Maryland generally may not rely on
the fact that cannabis is illegal under federal law to justify an arrest
or search based solely on the odor of cannabis.30 Although we

  29
     We express no view on the topic in other contexts.
  30
     To be clear, there may be some circumstances under which
Maryland police officers are participating in joint investigations with
180                                                    [107 Op. Att’y

cannot say with certainty how the courts would decide the question
if squarely presented, we assume for now that a Maryland officer
would not be able to rely on federal cannabis law to justify a search
(of either vehicles or persons) based on the odor of cannabis.

      With that caveat, we begin our analysis of the General
Assembly’s questions by making clear that, once the use and
possession of cannabis under certain circumstances becomes legal,
the odor of cannabis will—at the very least—still be a factor that
officers may use to establish probable cause to conduct a search.
After all, “[t]he probable-cause standard . . . depends on the totality
of the circumstances,” Lewis, 470 Md. at 21 (quoting Pringle, 540
U.S. at 370-71), and “[a] factor that, by itself, may be entirely
neutral and innocent, can, when viewed in combination with other
circumstances, raise a legitimate suspicion in the mind of an
experienced officer,” Ransome v. State, 373 Md. 99, 105 (2003).
Thus, regardless of whether the odor of cannabis standing alone
will be enough to establish probable cause for a search, we believe
that the odor will, at the very least, still be a relevant factor in the
“flexible, all-things-considered approach” to assessing probable
cause. Florida v. Harris, 568 U.S. 237, 244 (2013); cf. Bailey v.
State, 412 Md. 349, 382 (2010) (“The odor of ether is an innocent
factor without context, but the totality of the circumstances may
lead to a conclusion that the lawful substance is associated with a
criminal purpose.”).

      Indeed, courts in other states that have legalized some use and
possession of cannabis have held that the odor of cannabis is at
least a relevant factor in determining whether a police officer’s
search is justified. See Commonwealth v. Barr, 266 A.3d 25, 44
(Pa. 2021) (holding, in light of a state law legalizing possession and
use of cannabis for medical purposes, that “the odor of [cannabis]
alone does not amount to probable cause to conduct a warrantless
search of a vehicle but . . . may be considered as a factor in
examining the totality of the circumstances”); People v. Hill, 162
N.E.3d 260, 265 n.2 (Ill. 2020) (recognizing, in a state that had
legalized medical cannabis use, “the smell and presence of
cannabis undoubtedly remains a factor in a probable cause
determination”); People v. Zuniga, 372 P.3d 1052, 1054 (Colo.
2016) (holding, since passage of a state constitutional amendment
legalizing some use and possession of cannabis, that “the odor of

federal officers, see, e.g., Md. Code Ann., Pub. Safety (“PS”) § 2-
412(c)(12), or are deputized to act on behalf of the federal government,
see, e.g., 21 U.S.C. § 878; PS § 2-412(d). We do not consider here how
those situations might affect a Maryland officer’s authority to rely on
federal law in conducting a search based on the odor of cannabis.
Gen. 153]                                                            181

[cannabis] is relevant to the totality of the circumstances test and
can contribute to a probable cause determination”).
      The more difficult questions are whether, when some use and
possession of cannabis becomes legal in Maryland, the odor of
cannabis standing alone will be enough to justify a police officer’s
search of a vehicle or a police officer’s investigatory stop of an
individual. Cf. Zuniga, 372 P.3d at 1060 n.6 (declining to decide,
after Colorado legalized possession of recreational cannabis,
whether the odor of cannabis alone would support probable cause
to search a vehicle). Obviously, even though the Maryland courts
have held that the odor of cannabis alone could support vehicle
searches and investigatory stops under the State’s
decriminalization regime, the fact that some amount of cannabis
will, beginning July 1, 2023, be fully legal to possess under State
law raises new questions about whether the odor of cannabis, by
itself, justifies those actions.

      Before offering our opinion as to what Maryland’s appellate
courts would decide, we emphasize that we are not writing on a
blank slate. The Court of Appeals has already analyzed how the
State’s shift to decriminalization has affected the authority of
officers to conduct searches and to make arrests based on the odor
of cannabis standing alone. Our task here is to predict as best as
we can, based on that body of precedent, how the Court of Appeals
would rule, regardless of how we might have approached the
question on a blank slate. With that understanding of our role, we
turn to the General Assembly’s questions.

       1.   Searches of Vehicles and Their Occupants

     We first consider whether, when possession of up to 1.5
ounces of cannabis becomes legal, officers will still have probable
cause under the automobile exception to search a vehicle based on
the odor of cannabis standing alone.31

      In our view, although not entirely clear, the Court’s reasoning
in Robinson suggests that the Court would conclude that the odor
of cannabis coming from a vehicle, standing alone, still justifies a
warrantless search of the vehicle under the impending partial
legalization scheme, on the ground that it will still provide an
  31
     The Court of Appeals acknowledged in In re D.D. that voters would
decide during the November 2022 election whether to approve the
legalization of some use and possession of cannabis, but the Court
declined to offer any opinion as to legalization’s potential impact on the
Court’s Fourth Amendment jurisprudence. 479 Md. at 232 n.6.
182                                                   [107 Op. Att’y

officer with probable cause to believe that the vehicle contains
evidence of a crime. Robinson, 451 Md. at 133-34. We recognize
that the Court’s opinion in Robinson was “based largely on the
idea” that, under the State’s decriminalization regime, possession
of cannabis in any amount remains illegal (and, thus, contraband),
In re D.D., 479 Md. at 226—a rationale that will no longer apply
after the partial legalization of cannabis. The Court also repeatedly
emphasized in its opinion that “decriminalization is not . . .
legalization.” Robinson, 451 Md. at 99, 125.

      But, although the Court in Robinson focused on the fact that
cannabis in any amount remains contraband under the State’s
decriminalization regime, the Court also relied on a second,
“separate” rationale: that the odor of cannabis emanating from a
vehicle “provides probable cause to believe that [the] vehicle
contains evidence of a crime.” Id. at 133. While acknowledging
that the odor may be indicative of the non-criminal activity of
“possession of less than ten grams of [cannabis],” the Court
concluded that the odor was “just as indicative of crimes such as
the possession of more than ten grams of [cannabis], possession of
[cannabis] with the intent to distribute, or the operation of a vehicle
under the influence of a controlled dangerous substance.” Id. at
133-34 (emphasis added). Although this “separate” rationale was
discussed in only one paragraph of the Court’s decision in
Robinson, the Court has repeatedly reaffirmed that view in its later
decisions. See Pacheco, 465 Md. at 328-29 (quoting Robinson, 451
Md. at 134); Lewis, 470 Md. at 25 (same); In re D.D., 479 Md. at
226-27 (quoting Robinson, 451 Md. at 133-34).

      That separate rationale is important because Maryland’s
impending legalization scheme does not provide for full
legalization. Even under that partial legalization scheme, some
amounts of cannabis will remain illegal to possess: an amount
greater than 1.5 ounces but less than 2.5 ounces will be subject to
civil penalties, and possession of 2.5 ounces or more will be subject
to criminal penalties. 2022 Md. Laws, ch. 26, § 4 (amending CL
§§ 5-101, 5-601). Indeed, the crimes mentioned in Robinson as
providing probable cause to search a vehicle based on the odor of
cannabis will all remain crimes under the proposed partial
legalization scheme, though the amount of cannabis necessary to
trigger criminal penalties for simple possession will increase from
10 grams (about 0.35 ounces) to 2.5 ounces (about 71 grams). See
supra at 158-59 & n.9, n.11. While this new amount will be about
seven times greater than the current criminal amount, 2.5 ounces is
Gen. 153]                                                          183

not so much that it could not be concealed in a vehicle.32 And the
Court’s observation that the odor of the drug can indicate criminal
activity will remain true, even once the criminal amount of
cannabis increases from 10 grams to 2.5 ounces.

      We acknowledge, of course, that probable cause “deal[s] with
probabilities.” Gates, 462 U.S. at 231. As a matter of common
sense, we expect that an increase in the amount of cannabis
necessary to trigger criminal penalties will lead to an increase in
the number of people lawfully possessing and using cannabis. If
so, the level of probability that the odor of cannabis connotes the
possession of a criminal amount of cannabis will likely diminish.
Indeed, the Court of Appeals itself has recognized (in the context
of the odor of cannabis on a person) that a change in the drug’s
legal status can reduce the certainty that the odor is associated with
a crime. See In re D.D., 479 Md. at 232 (concluding that “partial
decriminalization has reduced the level of certainty associated with
the odor of [cannabis] on a person from probable cause that the
person has committed a crime to reasonable suspicion that the
person has committed a crime or is in the process of committing a
crime”).

      But, even if the smell of cannabis becomes less indicative than
before of the possession of a criminal amount of cannabis, probable
cause does not require an officer to establish by a preponderance of
the evidence that the car contains evidence of a crime. Freeman,
249 Md. App. at 301-02. Probable cause in this context requires
only a “fair probability” that evidence of a crime is present,
Robinson, 451 Md. at 109 (quoting Harris, 568 U.S. at 244), not
that the odor of cannabis is more likely associated with criminal
rather than non-criminal activity.

     More importantly, the Court of Appeals has also identified
other crimes, besides simple possession, that are associated with
the odor of cannabis in vehicles: driving while impaired by
cannabis and “crimes involving the distribution of [cannabis],”
such as possession of cannabis with the intent to distribute.
Robinson, 451 Md. at 133-34. In other words, even if the
possibility that the car might contain evidence of one of these
crimes would be insufficient on its own to rise to the level of
probable cause, the combined probability that the car contains
evidence of at least one of those crimes might provide an officer
  32
     An ounce of cannabis, sometimes referred to as a “zip of weed,”
“usually fits comfortably into” a Ziploc bag. Will Vance, A Zip of Weed:
What the Heck Is It and How Much Does It Cost?, Magnetic Magazine
(Sept. 8, 2022), https://www.magneticmag.com/2022/09/zip-of-weed/.
184                                                      [107 Op. Att’y

with probable cause. And if legalization increases the number of
people who possess and use the drug, one might reasonably expect
an increase in the incidents of driving while impaired by cannabis.
See, e.g., National Highway Traffic Safety Admin., Marijuana-
Impaired Driving: A Report to Congress, at 17 (July 2017).33
Similarly, because the impending legalization scheme does not yet
include a legal marketplace for buying and selling recreational
cannabis in Maryland, we cannot say that incidents of unlawful
distribution of cannabis and the possession of cannabis with intent
to distribute are likely to diminish.

     In fact, in the absence of a legal marketplace for recreational
cannabis, the odor of cannabis coming from a vehicle will
presumably still be highly indicative that the car may contain
evidence of unlawful distribution, even if the dealer is not among
the vehicle’s occupants.34 After all, to lawfully search a vehicle
under the Fourth Amendment, an officer need not suspect an
occupant of criminal activity; the officer need only have probable
cause to believe that the vehicle contains contraband or evidence of
a crime. See, e.g., Harris, 568 U.S. at 243; see also Zurcher v.
Stanford Daily, 436 U.S. 547, 556 (1978) (“The critical element in
a reasonable search [of property] is not that the owner of the
property is suspected of crime but that there is reasonable cause to
believe that the specific ‘things’ to be searched for and seized are
located on the property to which entry is sought.”); Wyoming v.
Houghton, 526 U.S. 295, 302 (1999) (recognizing that this
principle applies to warrantless searches of automobiles); 2 Wayne
R. LaFave, Search & Seizure: A Treatise on the Fourth Amendment

  33
       We acknowledge that, in cases of suspected drunk driving, the odor
of alcohol may establish reasonable suspicion of impaired driving but
not probable cause to search a vehicle. See, e.g., Ferris v. State, 355 Md.
356, 391 (1999) (“Bloodshot eyes, in conjunction with the odor of
alcohol emanating from the person, would ordinarily provide the police
with reasonable suspicion that a driver was under the influence of
alcohol.”). But, unlike cannabis, there is no amount of alcohol that is
illegal for adults to possess. Moreover, there is no crime of possession
of alcohol with intent to distribute. Thus, the odor of alcohol alone does
not raise the same overall level of suspicion of contraband or criminal
activity as does the odor of cannabis.
    34
       We do not mean to suggest that, beginning July 1, 2023, everyone
in possession of recreational cannabis in Maryland will necessarily have
purchased it from an illegal dealer in the State; some people will have
grown it themselves or have purchased it in another jurisdiction with a
legal marketplace for recreational cannabis. But, again, probable cause
does not require a more-than-fifty-percent likelihood that evidence of a
crime would be found, only a “fair probability.” Gates, 462 U.S. at 238.
Gen. 153]                                                            185

§ 3.1(b) (6th ed. 2020) (recognizing that “probable cause to search
a particular place may exist without there also being probable cause
to arrest a person who occupies that place,” and “there can be
probable cause to search a vehicle without there also being
probable cause to arrest the owner or operator of that vehicle”).35
Thus, at least until the State has established a legal marketplace for
cannabis, the odor of cannabis will still suggest that the car may
contain evidence of the crime of illegal distribution.36
      We acknowledge that some courts in other states have
concluded that the odor of cannabis cannot, without more, establish
the requisite probable cause when at least some use and possession
of the drug is no longer subject to criminal or civil penalties. For
example, in Pennsylvania, after lawmakers legalized the possession
and use of cannabis for medical purposes, the state supreme court
concluded that the odor of cannabis “alone cannot create probable
cause to justify a search” of a vehicle. Barr, 266 A.3d at 28, 41.
The court reasoned that a “lawful activity cannot alone be the basis
for probable cause,” and “it is simply not a crime for an individual
to possess or use [cannabis] if the requirements of” the state’s
medical cannabis statute “have been satisfied.” Id. at 43. “Thus,”
the court concluded, “one’s liberty may not be abridged on the sole
basis that a law enforcement officer detected the smell of
[cannabis], because, to do so, would eliminate individualized
suspicion required for probable cause and would misapply the
totality-of-the-circumstances test.” Id.37

  35
      In addition to the possibility that the car will contain evidence of
one of the crimes listed in Robinson, there is also still at least some
additional possibility that the odor of cannabis is indicative of the
possession of contraband, even if the amount is not criminal to possess.
Under the revised statute, possession of an amount greater than 1.5
ounces but less than 2.5 ounces would be a civil violation and that
cannabis would thus be contraband. That possibility is surely not enough,
on its own, to justify a search of the vehicle but it adds to the overall
possibility that the vehicle contains contraband or evidence of a crime.
   36
      We need not decide here whether the same would be true once
Maryland has established a legal marketplace for the sale of cannabis,
though—even then—cannabis will remain evidence of a crime under
many circumstances.
   37
      In Michigan, another state that has enacted a statute legalizing
cannabis use for medical purposes, the intermediate appellate court has
said that the odor of burnt cannabis, standing alone, can still establish
probable cause to search a vehicle that is in a public place, because the
statute does not permit the use of cannabis in public. See People v.
Anthony, 932 N.W.2d 202, 206-07, 213, 215 (Mich. Ct. App. 2019)
186                                                        [107 Op. Att’y

      Similarly, the intermediate appellate court of Illinois, where
an adult may now legally possess up to 30 grams of cannabis,
recently held that “the smell of . . . burnt cannabis, without any
corroborating factors, is not enough to establish probable cause to
search [a] vehicle.” People v. Stribling, ---N.E.3d---, 2022 WL
4299289, at *4, *6 (Ill. App. Ct. Sept. 19, 2022). In that case, an
officer smelled the odor of burnt cannabis emanating from a
vehicle, and the driver said that “someone (he did not state that it
was himself) had smoked in the vehicle ‘a long time ago.’” Id. at
*5. Finding this evidence insufficient to establish probable cause
to search the vehicle, the court observed that, given the state’s
decision to legalize possession of some amount of cannabis, the
smell of cannabis alone would no longer “lead a reasonable officer
to conclude that there was a substantial chance of criminal activity
afoot.” Id. The Court of Appeals of Oregon also reached a similar
conclusion, under a provision of the Oregon Constitution which
permits a police officer to extend a traffic stop “to conduct a
criminal investigation” unrelated to the “purpose of the traffic stop”
if the officer has “reasonable suspicion of criminal activity.” State
v. Moore, 488 P.3d 816, 819 (Or. 2021) (discussing Or. Const., Art.
I, § 9). The Oregon court held that, because “the possession and
transport of [cannabis], in a variety of amounts and forms, is now
legal” in the state, even a “very strong odor” of cannabis is “not a
specific enough articulation to adequately support reasonable
suspicion that [cannabis] [is] therefore present in [a] vehicle in an
unlawful quantity.” Id. at 819-21. Given that “reasonable suspicion”
is a lower standard than probable cause, that reasoning suggests
that the Oregon court would find that the odor of cannabis no longer
provides probable cause to search a vehicle under the Fourth
Amendment.38

(involving an officer who smelled the odor of burnt cannabis coming
from a vehicle parked on a public street). But the court has said that the
odor of fresh (i.e., unburnt cannabis) does not, standing alone, permit a
warrantless search of a vehicle, without some “basis to believe that a
suspect’s actions, i.e., the use or possession of the [cannabis], fall outside
the protections of the” statute. See People v. Moorman, 952 N.W.2d 597,
601-02 (Mich. Ct. App. 2020) (per curiam) (finding that an officer had
probable cause to search a vehicle based on the odor of fresh cannabis
and the driver’s denial that the vehicle contained any cannabis, because
the denial was “inconsistent with [the officer’s] testimony that he
smelled the odor of fresh [cannabis]” and, thus, suggested that the vehicle
contained an amount greater than that allowed under the statute).
   38
      Other courts have said that merely decriminalizing some use and
possession of cannabis means that the odor of the drug, standing alone,
no longer establishes probable cause to search a vehicle. In a series of
Gen. 153]                                                            187

     As the above discussion demonstrates, those courts that have
concluded that the odor of cannabis no longer provides probable
cause for a search have grounded their decisions in the fact that the
odor will often be associated with noncriminal activity. But our
Court of Appeals has so far departed from this line of thinking,
concluding instead that, because the odor of cannabis is “just as
indicative” of criminal activity as noncriminal activity, it is
reasonable to permit an officer to conduct a search of a vehicle that
smells of cannabis. Robinson, 451 Md. at 133-34. Indeed, the
Court expressly declined to follow the Massachusetts high court’s
decision in Overmyer (which had found the odor of cannabis to be
insufficient to provide probable cause even under a
decriminalization regime), noting that such a conclusion would
have “the effect of precluding all warrantless searches of vehicles
based on the odor of [cannabis], which would not be a salutary
development in Maryland.” Id. at 133.39

cases decided under a then-existing decriminalization scheme, the
Supreme Judicial Court of Massachusetts concluded that “a warrantless
search is not justified based solely on the smell of [cannabis], whether
burnt or unburnt,” Commonwealth v. Overmyer, 11 N.E.3d 1054, 1059-
60 (Mass. 2014), because an officer must suspect “criminal, as opposed
to merely infractionary, conduct,” Commonwealth v. Cruz, 945 N.E.2d
899, 908-09 (Mass. 2011), and “a human nose can[not] discern reliably
the presence of a criminal amount of [cannabis], as distinct from an
amount subject only to a civil fine,” Overmyer, 11 N.E.3d at 1059.
Likewise, the Supreme Court of New Hampshire held that, under a
decriminalization scheme, the odor of cannabis emanating from a
vehicle, standing alone, no longer supports even “reasonable, articulable
suspicion that a person possesses an illegal quantity of marijuana.” State
v. Francisco Perez, 239 A.3d 975, 980, 986 (N.H. 2020). The New
Hampshire court reasoned that “the odor of marijuana may indicate both
criminal and non-criminal activity,” id. at 984, and “the case-by-case
nature of the reasonable, articulable suspicion analysis counsels against
a per se rule,” id. at 986. Obviously, those courts would come to the
same conclusion under a legalization scheme.
    39
       We think it likely that our Court of Appeals would also find the
Pennsylvania Supreme Court’s decision in Barr, which was decided four
years after Robinson, unpersuasive. As noted above, the Barr Court
concluded that legalization of cannabis only for medical purposes
rendered the odor of cannabis, standing alone, insufficient to establish
probable cause to justify a search. Barr, 266 A.3d at 28, 41. But that
conclusion clashes with Robinson, which held that the odor of cannabis
still provides probable cause for a search in Maryland, notwithstanding
the fact that Maryland law already permitted possession and use of
cannabis for medical purposes. See Robinson, 451 Md. at 135-37
(recognizing “the ability of eligible persons to possess and/or use
[cannabis] for medical purposes,” but making no mention of that fact in
its analysis of the probable cause issue).
188                                                  [107 Op. Att’y

      To be sure, the Court of Appeals may ultimately decide that,
after partial legalization takes effect, a search based solely on the
odor of cannabis is no longer “reasonable”—the touchstone of
Fourth Amendment law. That is, the Court could conclude that the
partial legalization of cannabis, given that it changes the default
treatment of recreational cannabis under Maryland law, is
sufficiently different from decriminalization to justify a different
result. But, although the Court might ultimately decide the
reasoning in Robinson should no longer apply, that is for the Court,
not for us, to decide. In the meantime, we must faithfully adhere
to the logic of that decision. In doing so, we note that the Court
expressed concern that prohibiting officers from “conduct[ing]
warrantless searches of vehicles based on the odor of [cannabis]”
“would permit a myriad of crimes to go undetected.” Id. The
Court’s analysis also emphasized that “[w]hether a search is
reasonable depends on the public interest versus an individual’s
right to be free from arbitrary interference” by police. Id. at 108.
And as the Court explained in subsequent decisions, the search of
a vehicle does not raise the same fundamental privacy concerns as
the arrest and search of a person, Lewis, 470 Md. at 26, because of
the “diminished expectation of privacy one has in an automobile,”
In re D.D., 479 Md. at 228.

      The foregoing leads us to believe that, under the impending
partial legalization scheme, the Court of Appeals would still likely
consider the odor of cannabis, standing alone, sufficient to establish
probable cause to search a vehicle, at least until the General
Assembly has established a legal marketplace for the sale of
cannabis and possibly even afterwards. Although it is possible that
the Court could conclude that the certainty associated with the odor
of cannabis emanating from a car will diminish from probable
cause to mere reasonable suspicion, cf. In re D.D., 479 Md. at 232
(concluding the same with respect to decriminalization’s effect on
the odor of cannabis emanating from a person), we cannot say that
with confidence. The Court has repeatedly emphasized the
diminished expectation of privacy in vehicles as compared to
persons, e.g., Lewis, 470 Md. at 26, and has shown reluctance to
preclude all warrantless searches of vehicles based on the odor of
cannabis, Robinson, 451 Md. at 132-33. Moreover, vehicles could
be used by impaired drivers and could easily conceal a criminal
amount of cannabis or evidence of illegal distribution or possession
of the drug with the intent to distribute it. Collectively, these
factors lead us to believe that, under the impending partial
legalization scheme, the Court of Appeals would more likely still
hold that the odor of cannabis, standing alone, establishes probable
cause to search a vehicle.
Gen. 153]                                                            189

      We hasten to add that the certainty of our opinion is limited
by the relative lack of legal authority addressing the effect that
partial legalization of cannabis has had on officers’ authority to
conduct searches based on the odor of cannabis. We also lack a
firm idea, from either the legislative history of the 2022 cannabis
bills or the public record, of how many Marylanders will likely
possess and use cannabis under the impending legalization scheme,
how common the odor of cannabis in vehicles might be as a result,
and exactly how indicative that odor will be of criminal activity. In
addition, the fact that the use of medical cannabis and hemp are
legal under certain circumstances could also impact the
reasonableness of an officer’s belief that the odor of cannabis (or
what seems to be cannabis40) is indicative of criminality. But none
of the Court of Appeals decisions thus far have addressed the
impact, if any, that medical cannabis or hemp may have on this
question.

      In short, our opinion is simply our best effort to predict how
the Court of Appeals would rule in an area of the law that remains
highly uncertain. Given this uncertainty, police officers should be
aware that there is some risk that a court might suppress evidence
that an officer obtained in a search of a vehicle based solely on the
odor of cannabis.

     That said, the Legislature does have some authority to resolve
this uncertainty. While the General Assembly cannot legislate
what the Fourth Amendment permits, a state does have “power to
impose higher standards on searches and seizures than required by
the Federal Constitution if it chooses to do so.” Cooper v.
California, 386 U.S. 58, 62 (1967). Several other states have
  40
      As noted above, hemp is legal and distinct from cannabis, but some
criminal defendants have argued that the odor of cannabis is
indistinguishable from that of hemp. See, e.g., State v. Teague, -- S.E.2d
--, 2022 WL 16558096, at *3 (N.C. Ct. App. 2022); Gowen v. State, 860
S.E.2d 828, 831 (Ga. Ct. App. 2021). We are aware of only two
Maryland cases in which a defendant made this argument on appeal. In
the first case, the Court of Special Appeals concluded in an unreported
decision that the record did not establish “that [cannabis] and hemp emit
identical odors such that an officer cannot distinguish between them.”
Hall v. State, No. 1355, Sept. Term, 2021, 2022 WL 4243950, at *4 (Md.
Ct. Spec. App. Sept. 15, 2022). We are, of course, not equipped to
resolve those sorts of factual questions in our advisory opinions. In the
second case, the intermediate appellate court held in an unreported
decision that, under Robinson, an officer had probable cause to search a
vehicle based on what he perceived to be the odor of cannabis. Jerome
v. State, No. 1855, Sept. Term, 2021, 2022 WL 17337634, at *1 (Md. Ct.
Spec. App. Nov. 30, 2022) (per curiam).
190                                                          [107 Op. Att’y

enacted legislation prohibiting or limiting police from conducting
searches based on the odor of cannabis.41 But absent similar
legislation in Maryland, it is our opinion that, under the impending
legalization scheme, police will likely still have the authority to
conduct searches of vehicles based solely on the odor of cannabis.
      Like under current law, however, the odor of cannabis coming
from a vehicle will not, standing alone, permit police to search the
vehicle’s occupants. The Court of Appeals has already made clear
that officers must be able to point to something more to justify the
arrest and search of an occupant. Pacheco, 465 Md. at 332.
Legalization of some possession and use of cannabis will not
disrupt that holding.

      As a side note, we think it will make no difference to our
analysis whether an officer detects the odor of burnt cannabis or
the odor of fresh (i.e., unburnt) cannabis. Although there is some
authority outside Maryland that “the odor of unburnt, rather than
burnt, [cannabis] could be more consistent with the presence of
larger quantities,”42 and that the odor of burnt cannabis is more
consistent with driving under the influence of the drug,43 the Court
of Appeals has, so far at least, not attributed any special
significance to whether an officer smelled fresh or burnt cannabis
when the Court has affirmed the authority of police to conduct
vehicle searches based solely on the odor of cannabis. Compare

   41
       See, e.g., Conn. Gen. Stat. Ann. § 54-33p; N.J. Stat. Ann. § 2C:35-
10c; N.Y. Penal Law § 222.05(3), (4); Va. Code Ann. § 4.1-1302. In
California, where individuals 21 and older may possess and use up to
28.5 grams of cannabis, the legislature has not explicitly said that the
odor of cannabis may not establish probable cause to search a vehicle.
But lawmakers have said that “[c]annabis and cannabis products
involved in any way with conduct deemed lawful by [statute] are not
contraband nor subject to seizure, and no conduct deemed lawful by
[statute] shall constitute the basis for detention, search, or arrest.” Cal.
Health & Safety Code § 11362.1(a), (c). A California appellate court has
said that this statute “definitively affects probable cause determinations”
and “undercuts the continued viability of” an earlier case that held “that
the odor of marijuana alone establishes probable cause.” People v.
Johnson, 264 Cal. Rptr. 3d 103, 110-11 (Cal. Ct. App. 2020).
   42
      Overmyer, 11 N.E.3d at 1058 (but going on to say that “it does not
follow that such an odor reliably predicts the presence of a criminal amount
of the substance”); see also Zullo v. State, 205 A.3d 466, 502 (Vt. 2019)
(asserting that “the faint smell of burnt [cannabis] is far less probative as to
whether a car contains [cannabis] than, say, an overpowering odor of fresh
[cannabis] emanating from the trunk of a car”).
   43
      State v. Bowen, 481 P.3d 370, 374 (Or. Ct. App. 2021).
Gen. 153]                                                           191

Robinson, 451 Md. at 99-106 (holding that officers’ detection of a
strong odor of “fresh” (i.e., unburnt) cannabis coming from
vehicles authorized the search of those vehicles), with, e.g.,
Pacheco, 465 Md. at 318, 330 (recognizing, in a case involving a
vehicle that smelled of burnt cannabis, that the odor permitted a
search of the vehicle but not, without more, the vehicle’s driver).

      Finally, although this issue was not specifically mentioned in
the Legislature’s opinion request, we also note that the impending
legalization scheme calls into question the ability of officers to
obtain the necessary probable cause to search a vehicle by using
dogs trained to detect the odor of cannabis. It is clearly not a
“search” under the Fourth Amendment for officers to use their own
noses to smell cannabis emanating from a car, because a person has
no reasonable expectation of privacy in odors that waft into a public
space, such as a highway, where an officer (or any other person)
could smell them. See supra footnote 20. But a dog’s sense of
smell is more than 100,000 times stronger than a human’s, see
Reid, supra, at 183, allowing a dog to detect odors that may be
imperceptible to a person and thus raising different questions about
whether a dog sniff intrudes on reasonable expectations of privacy
and thereby constitutes a search.

      Although (as explained above) the Supreme Court has
historically concluded that a dog’s sniff is generally not a “search”
under the Fourth Amendment—despite the fact that other sense-
enhancing techniques can sometimes constitute a search for which
probable cause is required, cf. Kyllo, 533 U.S. at 34-35—the
Court’s rationale for that conclusion may be undermined by the
partial legalization of cannabis. More specifically, the Supreme
Court has said up to this point that dog sniffs generally are not
searches because no one has a legitimate expectation of privacy in
contraband and trained dogs historically have been used to alert
only to the presence or absence of contraband. Place, 462 U.S. at
707.44 But, once Maryland’s partial legalization scheme takes effect

  44
     See also Andreas, 463 U.S. at 771 (recognizing that a “search”
occurs only when a government inspection “intrude[s] upon a legitimate
expectation of privacy”); Caballes, 543 U.S. at 409 (concluding that “the
use of a well-trained narcotics-detection dog—one that ‘does not expose
noncontraband items that otherwise would remain hidden from public
view’— . . . generally does not implicate legitimate privacy interests”)
(emphasis added) (quoting Place, 462 U.S. at 707); 1 Wayne R. LaFave,
Search and Seizure: A Treatise on the Fourth Amendment, § 2.2(g) (6th
ed. 2020) (noting “the unique nature of the investigative technique” of
using canines, whose sniff can “disclose[] only criminality and nothing
192                                                        [107 Op. Att’y

and cannabis in Maryland is no longer contraband in every instance,
it will no longer always be true that a dog’s sniff will be able to detect
only the presence or absence of contraband, as even a specially
trained dog cannot tell whether it is smelling a quantity of cannabis
that is greater or less than 1.5 ounces. See, e.g., Denise LaVoie, Since
the nose doesn’t know pot is now legal, K-9s retire, Associated Press,
May 29, 2021, https://apnews.com/article/va-state-wire-police-marijuana-
marijuana-legalization-253af1ba6e541060085108e027b367c1 (reporting
that police departments in states that have legalized cannabis have
retired cannabis-detecting dogs because they “cannot distinguish
between a small, legal amount of [cannabis] or a larger, still-illegal
amount of the drug”); see also Douglas A. Berman & Alex Kreit,
Ensuring Marijuana Reform Is Effective Criminal Justice Reform,
52 Ariz. St. L.J. 741, 765-66 (2020) (arguing that, “once [cannabis]
is no longer considered contraband, the police may no longer be
permitted to conduct suspicionless drug dog sniffs using dogs that
are trained to detect [cannabis]”). Because such a dog could alert
to “noncontraband items” (i.e., lawful amounts of cannabis) “that
otherwise would remain hidden from public view,” a dog’s sniff
under those circumstances appears to “implicate legitimate privacy
interests.” Caballes, 543 U.S. at 409.

      Thus, based on existing Supreme Court precedent, there is a
significant risk that Maryland’s appellate courts would conclude
that a dog sniff for cannabis is a search. See Andreas, 463 U.S. at
771; see also Maryland v. Macon, 472 U.S. 463, 469 (1985) (“A
search occurs when ‘an expectation of privacy that society is
prepared to consider reasonable is infringed.’”) (quoting United
States v. Jacobsen, 466 U.S. 109, 113 (1984)); People v. McKnight,
446 P.3d 397, 408-10 (Colo. 2019) (holding that a dog sniff is a
search that must be supported by probable cause under Colorado
law because “persons twenty-one or older may lawfully possess
[cannabis] in small amounts” in Colorado and, thus, “a drug-
detection dog that alerts to even the slightest amount of marijuana
can no longer be said to detect ‘only’ contraband”); Alex C.
Carroll, Weed, Dogs & Traffic Stops, 21 Wyo. L. Rev. 1, 6 (2021)
(arguing that “a dog sniff conducted during a routine traffic stop is
a Fourth Amendment ‘search’ in states that have legalized
marijuana”). And if a dog sniff indeed amounts to a “search” for
constitutional purposes under these circumstances, the officer
would have to establish probable cause before allowing the dog to
sniff the vehicle, as opposed to using the dog sniff to establish

else”); Reid, supra, at 183 (noting that, “if a dog is . . . trained to detect
ONLY the presence of odor emanating from an illegal substance, then
the dog, when it alerts, is detecting a substance that no one has a lawful
reason to possess”).
Gen. 153]                                                                193

probable cause to search the vehicle.45 Again, this is a novel area
of the law, and the doctrine could potentially evolve. All we can
do for the time being is provide our best advice based on how
current precedent might apply to these new circumstances. But
police departments need to be aware that the impending
legalization regime may change the way that drug-sniffing dogs—
at least those trained to detect cannabis—are viewed under the
Fourth Amendment.
        2.   Searches of Individuals Outside the Vehicle Context

      We next consider whether Maryland’s impending legalization
scheme will affect the authority of police officers to search
individuals based on the odor of cannabis outside of the vehicle
context. The Court of Appeals has already held that police cannot,
even under current law, arrest and search a person merely because
the person smells of cannabis. Lewis, 470 Md. at 17, 23. In that
context, unlike with vehicle searches, the police need probable
cause to believe that the specific person being arrested has
committed a felony or is committing a crime in the officer’s
presence, and the search involves a greater intrusion of privacy than
the search of a vehicle. E.g., id. at 20, 22, 25-26.

      In our view, this limitation on searches of persons incident to
arrest will remain true once it becomes legal for someone who is at
least 21 years old to possess up to 1.5 ounces. Under that scheme,
the reasoning of Lewis will still apply: Because “[t]he odor
of [cannabis] alone is not indicative of the quantity (if any) of
[cannabis] in someone’s possession,” id. at 23, officers will not be
able to know whether the scent is associated with a crime or with
the lawful use or possession of cannabis; thus, “[a]rresting and
   45
      It is possible, of course, that an officer could encounter a vehicle
occupied only by a driver whom the officer knows to be under 21 and,
thus, not entitled to possess any amount of cannabis; in that case, a dog’s
sniff for cannabis will still detect only the presence or absence of
contraband and thus would almost certainly not give rise to a
constitutional search under the logic of current precedent. In addition, it
is clear that police could still, even without first establishing probable
cause, use a canine trained to detect only those drugs that are illegal in
any quantity (such as heroin or cocaine), although that approach would
presumably require police departments to re-train police dogs or train
new dogs so that they do not alert to the odor of cannabis. See
Reid, supra, at 208 (asserting that “[l]aw enforcement dog handlers will
be the most affected by” the legalization of cannabis, and “police
departments . . . will have to train new drug dogs to detect the usual illegal
substances, such as heroin, cocaine, and methamphetamine, but exclude
the odor of [cannabis]”).
194                                                   [107 Op. Att’y

searching a person, without a warrant and based exclusively on the
odor of [cannabis] on that person’s body or breath, [will be]
unreasonable and [will] do[] violence to the fundamental privacy
expectation in one’s body,” id. at 26. If, however, other facts
arouse an officer’s suspicions, the odor of cannabis can be
considered among the totality of circumstances in determining
whether there is probable cause to arrest. See id. at 21; Ransome,
373 Md. at 105.
      Less certain is whether the Court of Appeals would still
permit brief investigatory stops based solely on the odor of
cannabis coming from a person. The Court of Appeals, in its recent
decision about investigatory stops under the current
decriminalization regime, said that “partial decriminalization has
reduced the level of certainty associated with the odor of [cannabis]
on a person from probable cause that the person has committed a
crime to reasonable suspicion that the person has committed a
crime or is in the process of committing a crime.” In re D.D., 479
Md. at 232. The Court could well conclude that partial legalization
also “change[s] the . . . landscape significantly,” id. at 225, further
reducing an officer’s level of certainty about whether the odor of
cannabis is indicative of criminal activity. After all, the Court has
recognized that reasonable suspicion cannot depend on factors
which are both consistent with innocent behavior and “too
commonplace to be probative in tending to show criminal activity.”
Ferris, 355 Md. at 386-87. “[F]actual circumstances which ‘describe
a very large category of presumably innocent travelers’ cannot, in
and of themselves, justify a seizure.” Id. (quoting Reid v. Georgia,
448 U.S. 438, 441 (1980)). Thus, it may be that the legalization of
some possession and use of cannabis will make the odor of cannabis
so common as to be legally insufficient to support a finding of even
reasonable suspicion. Cf. Moore, 488 P.3d at 819-21 (concluding,
in light of a state law permitting “the possession and transport of
[cannabis], in a variety of amounts and forms,” that even a “very
strong odor” of cannabis is “not a specific enough articulation to
adequately support reasonable suspicion that [cannabis] [is]
therefore present in [a] vehicle in an unlawful quantity”).

      On the other hand, the Court in In re D.D. described a stop as
“a relatively minor intrusion” on one’s “freedom of movement”
and emphasized “[t]he public interest in investigating and
prosecuting criminal offenses” and the Court’s desire to avoid
“significantly hamper[ing] the legitimate investigation of criminal
activity in Maryland.” 479 Md. at 233, 238, 241. The Court also
reaffirmed “key language” from Robinson “that the odor of
[cannabis] still provides evidence of a crime,” “even if it may not
Gen. 153]                                                         195

rise to the level of probable cause in every situation.” Id. at 235.
As already noted, the relevant crimes identified in Robinson
(possession of a criminal amount of cannabis and distribution
crimes) will remain crimes under the impending legalization
scheme. But perhaps most significantly, the Court observed that
“it would be peculiar if the odor of [cannabis] was sufficient to
meet the higher standard of probable cause needed to search a
vehicle, but insufficient to meet the lower standard of reasonable
suspicion needed to briefly stop a person on the street.” Id. at 236.
If we are correct that, under the legalization scheme, the odor of
cannabis will still authorize officers to search a vehicle, then it
seems likely that the Court of Appeals would hold that officers still
have the authority to briefly detain someone who smells of cannabis.

      As the Court emphasized in In re D.D., however, any detention
will have to “be brief, especially in light of the reality that many
individuals who choose to possess [cannabis] do so under the
criminal threshold.” Id. at 233-34. “[I]f the officer does not quickly
obtain additional information that provides probable cause to believe
that the person has committed a . . . criminal offense, the officer”
will have to “allow the person to go on their way.” Id. at 233.

                               III
                            Conclusion

      Although by no means clear, it is our opinion that, under the
impending legalization of some use and possession of cannabis, the
Court of Appeals would more likely hold that police officers can
still search a vehicle that smells of the drug. But the odor of
cannabis emanating from a vehicle will not, without more, permit
a police officer to search the vehicle’s occupants. The partial
legalization of cannabis also calls into question the use of drug-
sniffing dogs to establish probable cause for a vehicle search, if
those dogs are trained to detect cannabis. Beyond the vehicle
context, the odor of cannabis coming from a person, without more,
will not authorize a police officer to arrest and search that person,
but the odor will likely allow an officer to briefly stop the person
to investigate whether they have a criminal amount of cannabis.
                                    Brian E. Frosh
                                    Attorney General of Maryland
                                    Rachel A. Simmonsen
                                    Assistant Attorney General
Patrick B. Hughes
Chief Counsel, Opinions and Advice