[J-64-2019]

IN THE SUPREME COURT OF PENNSYLVANIA

EASTERN DISTRICT

SAYLOR, C.J., BAER, TODD, DONOHUE, DOUGHERTY, WECHT, MUNDY, JJ.

COMMONWEALTH OF PENNSYLVANIA,

Appellee

v.

TIMOTHY TRAHEY,

Appellant

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No. 38 EAP 2018

Appeal from the Order of Superior 

Court entered on 03/26/2018 at No. 

730 EDA 2017 (reargument denied 

05/23/2018), reversing and remanding 

the Order entered on 02/08/2017 in 

the Court of Common Pleas, 

Philadelphia County, Criminal 

Division, at No. CP-51-CR-0000422-

2016.

ARGUED: September 10, 2019

OPINION

JUSTICE WECHT DECIDED: April 22, 2020

In this discretionary appeal, we revisit the limitations that the Fourth Amendment 

to the United States Constitution places upon the collection of evidence from the body of 

a motorist suspected of driving under the influence of alcohol or controlled substances

(“DUI”), in light of the Supreme Court of the United States’ decisions in Missouri v. 

McNeely, 569 U.S. 141 (2013), Birchfield v. North Dakota, __ U.S. __, 136 S.Ct. 2160 

(2016), and Mitchell v. Wisconsin, __ U.S. __, 139 S.Ct. 2525 (2019) (plurality). This 

matter concerns the exigent circumstances doctrine.1

 

1

In Fourth Amendment jurisprudence, the exigent circumstances doctrine refers to 

an exception to the warrant requirement applicable where “the exigencies of the situation 

make the needs of law enforcement so compelling that a warrantless search is objectively 

reasonable under the Fourth Amendment.” McNeely, 569 U.S. at 148-49 (quoting 

Kentucky v. King, 563 U.S. 452, 460 (2011)).
[J-64-2019] - 2

The trial court granted Timothy Trahey’s motion to suppress the results of a blood 

test that revealed his blood alcohol concentration (“BAC”), finding no justification for the 

investigating officers’ failure to obtain a search warrant before conducting the test. On 

the Commonwealth’s appeal, the Superior Court reversed, opining that the 

Commonwealth’s evidence sufficiently established the existence of exigent 

circumstances, thus excusing the absence of a warrant. We reverse the order of the 

Superior Court.

I.

The facts giving rise to this appeal, as summarized from the suppression court’s 

findings, are as follows. On the evening of September 4, 2015, the Friday before Labor 

Day, 911 dispatchers received a report that a motorist had stricken a bicyclist with a 

pickup truck on the 4900 block of Wynnewood Avenue in Philadelphia. The accident was 

reported at 9:15 p.m., but, because the Philadelphia Police Department assigns a 

relatively low priority to vehicular accident response, police officers were not dispatched 

to the scene until 10:01 p.m. Officers Christopher Marchesani and Derrick Lewis arrived 

at the scene at approximately 10:04 p.m. The bicyclist already had been transported to 

a hospital, but ultimately died from the injuries sustained. A group of bystanders informed 

the officers that Trahey was operating the pickup truck when he collided with the bicyclist. 

Officer Marchesani approached Trahey, who confirmed that he was the driver. During 

his interaction with Trahey, Officer Marchesani noticed that Trahey smelled of alcohol, 

that his speech was slow and slurred, that his eyes were glassy, and that his gait was 

unsteady. Based upon these observations, Officer Marchesani arrested Trahey for DUI.

The officers had spent approximately thirty minutes at the accident scene before 

they departed to transport Trahey to the Police Detention Unit (“PDU”). While en route to 

the PDU, they were called back to the scene by officers of the Accident Investigation 
[J-64-2019] - 3

District (“AID”), a unit that specializes in the investigation of accidents involving critical 

injuries. After observing the indicia of Trahey’s intoxication, and learning that over an 

hour had passed since the accident, AID Officer Patrick Farrell became concerned with 

the timing of a BAC test.2 Accordingly, at 10:49 p.m., Officer Farrell sent Trahey to the 

PDU for a blood test.

AID Officer John Zirilli was the officer assigned to conduct breath and blood tests 

that evening. In accordance with a Department policy for the investigation of accidents 

involving serious injuries, Officer Zirilli selected a blood test rather than a breath test. No 

officer attempted to obtain a search warrant for the blood draw. Upon encountering 

Trahey, Officer Zirilli advised him of the requirements of Pennsylvania’s “implied consent” 

law,3 which, at the time, included warnings that the refusal to submit to chemical testing 

could result in legal consequences, including increased criminal penalties upon 

conviction. Trahey verbally acknowledged these warnings, stated that he would submit 

to a blood test, and signed the applicable form. However, Trahey did not check the box 

on the form indicating that he agreed to undergo blood testing. A nurse drew Trahey’s 

blood at 11:20 p.m.

Trahey was charged with DUI, homicide by vehicle while driving under the 

influence, homicide by vehicle, and involuntary manslaughter. During the pre-trial 

proceedings, however, the Supreme Court of the United States issued its decision in 

Birchfield. Drawing a constitutional distinction between breath and blood, the Birchfield 

 

2 The DUI statute provides, in relevant part, that “[a]n individual may not drive, 

operate or be in actual physical control of the movement of a vehicle after imbibing a 

sufficient amount of alcohol such that the alcohol concentration in the individual’s blood 

or breath” falls within specified ranges “within two hours after the individual has driven, 

operated or been in actual physical control of the movement of the vehicle.” 75 Pa.C.S. 

§ 3802(a)(2), (b), (c) (emphasis added).

3 See generally 75 Pa.C.S. § 1547.
[J-64-2019] - 4

Court held that a breath test may be conducted without a search warrant as a valid search 

incident to arrest. Birchfield, 136 S.Ct. at 2185. The same cannot be said of the 

“significantly more intrusive” blood test, the reasonableness of which “must be judged in 

light of the availability of the less invasive alternative of a breath test.” Id. at 2184. 

Following the Birchfield decision, on November 30, 2016, Trahey filed a motion to 

suppress the results of his blood test, asserting that the test was unconstitutional without

a search warrant.

On February 8, 2017, the trial court held a hearing on Trahey’s motion. Officer 

Zirilli testified regarding his interactions with Trahey, the procedure that he followed before 

having Trahey’s blood drawn, and his recitation of the “implied consent” warnings. Notes 

of Testimony, Suppression Hearing, 2/8/2017 (“N.T.”), at 6-22. Officer Zirilli confirmed 

that a blood test ordinarily is selected when a vehicular accident results in death or serious 

injury, and that he chose a blood test for that reason. Id. at 7, 38. However, Officer Zirilli 

acknowledged that an Intoxilyzer 8000 breath-testing machine was present in the room 

when he was interacting with Trahey. Id. at 23.

Officer Marchesani testified about his initial response to the accident scene and 

his investigation thereof. He established the beginning of the relevant time frame, 

confirming that the initial report of the collision was received at 9:15 p.m., and that he and 

his partner were dispatched to the scene at 10:01 p.m. Id. at 85-87. Officer Marchesani 

explained this temporal gap by describing the hierarchy pursuant to which police 

response is prioritized in Philadelphia. The highest priority is assigned to incidents 

requiring officer backup, then to reports involving weapons or robberies, then to burglaries 

or vandalism in progress, then to domestic violence reports, and finally to vehicular 

accident response. Id. at 46, 68-69.
[J-64-2019] - 5

AID Officer Farrell testified, accounting for the time that elapsed after AID officers 

took responsibility for the investigation. Officer Farrell detailed his concern for the timing 

of a BAC test upon learning that the accident had occurred approximately one hour before 

AID’s arrival at the scene. Id. at 97-98. Officer Farrell confirmed that AID officers 

transported Trahey to the PDU at 10:49 p.m. Id. at 99-100.

Finally, AID Officer Daniel Shead testified. Officer Shead detailed the 

responsibilities of various AID officers when they are on duty, as well as certain 

procedures involved in DUI investigation. He testified that, on the evening in question, 

two AID officers were on duty at AID headquarters and three officers were in the field, 

including himself. Id. at 108. Because one officer was assigned to answer the telephone 

and one officer was assigned to conduct chemical tests, Officer Shead opined that no 

one at the headquarters was available to begin preparing a search warrant before Trahey 

arrived. Id. at 109-11. He noted, however, that, had Trahey refused to submit to a blood 

draw, the officers “would have tried to secure a search warrant” for the test. Id. at 111.

With regard to the process for obtaining a search warrant and the time frame 

involved, Officer Shead detailed the steps that an officer would have to take in order to 

obtain a warrant. First, an officer must leave the accident scene and return to AID 

headquarters, which in this case would have taken between ten and fifteen minutes. Id.

at 113, 118. The officer then must write an affidavit, which may take twenty to thirty 

minutes. Id. at 113, 118. The officer must submit the affidavit to an Assistant District 

Attorney for review, which takes another ten to fifteen minutes. Id. at 113, 119. If 

approved, the officer must prepare the search warrant application on a typewriter. Id. at 

113. With the documents completed, the officer must contact the arraignment court and 

determine whether a bail commissioner is available to approve the warrant. Id. at 113-

114. Officer Shead opined a commissioner might be available right away, or the affiant 
[J-64-2019] - 6

might have to wait upwards of an hour, there being “no rhyme or reason” for the time 

variation. Id. at 113, 114, 120. Once a commissioner is available, the officer must travel 

from AID headquarters, which may take another ten minutes. Id. at 121. Waiting for a 

commissioner could then take between five and thirty minutes. Id. The bail 

commissioner’s review takes another five minutes. Id. at 122. All told, Officer Shead 

opined, the procedure for obtaining a search warrant at the time would take, at best, 

seventy to seventy-five minutes, but could take up to three hours. Id. at 122-23.

The court asked Officer Shead if he was aware that, due to the intervening change 

in the law, blood testing requires a search warrant absent exigent circumstances. Officer 

Shead stated his understanding that a search warrant is required if the suspect refuses 

to submit to chemical testing. Id. at 126-27. He opined that, had Trahey refused the 

blood draw, “then there would have been a warrant gotten that night because of the 

injuries that were sustained and whatever else happened at the accident.” Id. at 127. 

The court asked whether the officers would have requested a breath test in that situation, 

and Officer Shead replied: “No. We would have gotten a search warrant for the blood.” 

Id. at 128. Asked why the officers would choose a blood test over a breath test, Officer 

Shead explained that “a Breathalyzer only shows someone’s blood alcohol concentration” 

but does not reveal whether there are any “other intoxicants” such as controlled 

substances in the suspect’s system. Id. at 128. “A blood test shows everything.” Id. at 

129.

At the conclusion of the suppression hearing, the court placed its conclusions of 

law on the record, first opining that Trahey’s purported consent to the blood draw was 

invalid because he was warned that failure to comply could result in enhanced criminal 

penalties—a consequence held unconstitutional in Birchfield. Id. at 178-79. The court 

further rejected the Commonwealth’s assertion of exigent circumstances, noting that the 
[J-64-2019] - 7

officers did not give any consideration to applying for a search warrant because they 

believed that Trahey validly consented to the blood draw. The court rejected the claim of 

exigency, deeming it a post hoc rationale that did not motivate the officers at the time. Id.

at 180-81. The court further observed that all of the officers who encountered Trahey

noted that he smelled like alcohol, and that “[t]his is a case where a Breathalyzer could 

have been taken.” Id. at 181. Accordingly, finding no justification for a warrantless blood 

draw, the court granted Trahey’s motion to suppress the results of the blood test.

The Commonwealth filed an interlocutory appeal pursuant to Pa.R.A.P. 311(d),4

and the Superior Court reversed. Commonwealth v. Trahey, 183 A.3d 444 (Pa. Super. 

2018). The intermediate court first concluded that the suppression court erred by 

assessing the Commonwealth’s claim of exigency by reference to the officers’ actual 

beliefs and motivations, because the prevailing standard requires a court to “determine 

whether the warrantless search was objectively reasonable under the Fourth 

Amendment.” Id. at 451 (emphasis in original). Quoting this Court’s decision in 

Commonwealth v. Martin, 101 A.3d 706 (Pa. 2014), which, in turn, quoted the Supreme 

Court’s decision in Ashcroft v. al-Kidd, 563 U.S. 731, 736 (2011), the Superior Court 

observed that evaluating “reasonableness” under the Fourth Amendment requires a court 

to “ask whether the circumstances, viewed objectively, justify the challenged action. If 

so, that action was reasonable whatever the subjective intent motivating the relevant 

officials.” Trahey, 183 A.3d at 451 (quoting Martin, 101 A.3d at 721-22). Had the 

suppression court correctly viewed the facts under an objective standard, the Superior 

Court opined, “it would have found ample evidence to deny suppression of the blood 

evidence.” Id. at 452.

 

4 See Pa.R.A.P. 311(d) (authorizing an interlocutory appeal as of right from a 

suppression order “where the Commonwealth certifies in the notice of appeal that the 

order will terminate or substantially handicap the prosecution”).
[J-64-2019] - 8

Specifically, the Superior Court pointed to the officers’ testimonies regarding the 

desirability of testing a suspect’s BAC within two hours after the time of the accident and 

the fact that the officers did not arrive at the scene until nearly fifty minutes after the first 

emergency report. The court emphasized that the officers were not aware that the 

incident was DUI-related until their arrival and that there was additional delay resulting 

from the transfer of the investigation to the specialized AID officers. It further highlighted 

the “lack of manpower” available that evening, inasmuch as only five AID officers were 

on duty and they were responsible for all critical and DUI-related accident investigations 

in Philadelphia. Id. at 452. The court particularly highlighted Officer Shead’s testimony 

regarding the “practical problems” accompanying the process of obtaining a search 

warrant, and noted that the defense “did not contest the prosecution’s evidence that it 

would have taken officers anywhere from seventy minutes to three hours to successfully 

obtain a warrant.” Id. Based upon these facts, the Superior Court deemed it “reasonable 

to believe that the arresting officers were confronted with exigent circumstances, in which 

the delay necessary to obtain a warrant threatened the destruction of evidence.” Id. 

Accordingly, the court reversed the suppression order.5

We granted Trahey’s petition for allowance of appeal in order to review the 

Superior Court’s determination that the warrantless blood draw conducted in this case 

was justified by exigent circumstances.6

 

5 President Judge Emeritus John T. Bender concurred in the result of the Superior 

Court’s decision, but did not join the majority’s opinion.

6 Specifically, as rephrased in our order granting allowance of appeal, the question 

before this Court is: “Do the facts and circumstances in this case justify a warrantless 

blood draw under the exigent circumstances exception to the warrant requirement?” 

Commonwealth v. Trahey, 196 A.3d 603 (Pa. 2018) (per curiam).
[J-64-2019] - 9

II.

Trahey argues that the Commonwealth’s evidence regarding the difficulty of 

obtaining a search warrant was “speculative” because, no attempt to obtain a warrant 

having been made, it is unknown how long the process would have taken in this case. 

Brief for Trahey at 17. The Commonwealth’s central argument before the suppression 

court, Trahey contends, was that applying for a search warrant is time-consuming and 

that the alcohol in a suspect’s blood is metabolizing during that time, which is an argument 

that could apply to all DUI cases. Id. at 22-23. More fundamentally, given the ready 

availability of a breath test, the lawfulness of conducting such a test without a search 

warrant under Birchfield, and the absence of any suggestion that Trahey was impaired by 

any substance other than alcohol, Trahey argues that a blood test was wholly 

unnecessary. He posits that “[t]here cannot be exigent circumstances to obtain 

something that is not even needed in the first place.” Id. at 18 (emphasis omitted). Even 

if, arguendo, the officers had reason to suspect the presence of controlled substances in 

his system, Trahey contends that “illicit drugs take much longer than alcohol to 

metabolize,” and therefore a delay necessitated by a search warrant application would 

not risk the destruction of such evidence. Id. at 22.

Trahey further criticizes the practices of the Philadelphia Police Department. 

Taking aim at the officers’ delayed response time, as well as the asserted time constraints 

involved in the search warrant application process, Trahey questions the low priority 

assigned to vehicular accidents involving critical injuries and the decision to place only 

five AID officers on duty for all of Philadelphia that evening, the beginning of Labor Day 

weekend. Id. at 27. “If the Philadelphia Police Department is going to unnecessarily insist 

on using the far more intrusive blood test as opposed to a less intrusive and 

[c]onstitutionally permissible breath test,” Trahey argues, “then the department needs to 
[J-64-2019] - 10

set up an infrastructure that can timely process the required search warrant request.” Id. 

Along these lines, Trahey highlights that the High Court in Birchfield considered two cases 

arising in North Dakota, which, the Court noted, has only fifty-one state district judges and 

thirty-one magistrates, with no magistrates in twenty of the state’s fifty-three counties. Id.

at 24 (quoting Birchfield, 136 S.Ct. at 2181). Given that the Birchfield Court demanded

compliance with the warrant requirement for blood tests in North Dakota, where “relatively 

few state officials have authority to issue search warrants,” Birchfield, 136 S.Ct. at 2181, 

Trahey contends that there is no justification for applying a lower standard to the City of 

Philadelphia, “which has the type of substantial law enforcement and legal infrastructure 

that is required for a major city.” Brief for Trahey at 23.

Relatedly, to the extent that the delay in response time and the AID staffing 

limitations gave rise to an urgent need for a warrantless blood draw, Trahey argues that 

those circumstances were within the control of the police and, thus, that any exigency 

was one of the officers’ own making. Because police officers cannot rely upon exigent

circumstances “where the exigency derives from their own actions,” id. at 27 (quoting 

Commonwealth v. Demshock, 854 A.2d 553, 557 (Pa. Super. 2004)), Trahey urges this 

Court to reject the Superior Court’s analysis.

The Commonwealth, by contrast, disputes that the delays in this case were within

the officers’ control. Citing Officer Marchesani’s testimony regarding the hierarchy of 

incidents requiring police response, the Commonwealth asserts that police dispatchers 

must adhere to that system, that the officers did not choose when they would be 

dispatched to the accident scene, and that this “was not a situation where police were 

purposefully biding their time.” Brief for Commonwealth at 19-20. The Commonwealth 

appears to dispute the Superior Court’s characterization of the relative “lack of manpower” 

available that evening, and refers to testimony suggesting that there was a “higher-than-
[J-64-2019] - 11

normal number of officers on duty.” Id. at 16 (citing N.T. at 133). Notwithstanding the

above-average number of available officers, the Commonwealth maintains that there was 

no opportunity to apply for a search warrant. The Commonwealth emphasizes that the 

responding officers, through no fault of their own, were not dispatched to the accident 

scene until forty-six minutes after the first report of the collision, that they were unaware 

at that time that Trahey may have been intoxicated, and that approximately ninety-six 

minutes had elapsed by the time that they were able investigate, arrest, and transport 

Trahey to the PDU. Id. at 13-14. Even with their best efforts, the Commonwealth 

highlights, the officers here were unable to have Trahey’s blood drawn until 125 minutes 

after the collision. Id. at 14. Any further delay, the Commonwealth argues, “would have 

threatened, if not guaranteed, the destruction of evidence” of Trahey’s BAC. Id.

With regard to the time-sensitivity of the investigation, the Commonwealth stresses 

that the “optimal period” to obtain BAC evidence from a DUI suspect is within two hours 

after the suspect’s last operation of the vehicle. Id. at 14 (citing 75 Pa.C.S. § 3802(a)-

(c)). Given the constant dissipation of the alcohol in Trahey’s bloodstream, the 

Commonwealth contends that “it would have been impossible to secure a warrant within 

a reasonable timeframe to preserve reliable evidence.” Id. at 15. In this regard, the 

Commonwealth emphasizes Officer Shead’s testimony that it would have taken at least 

seventy minutes to obtain a search warrant, but that it could have taken as long as three 

hours. Id. at 15-16. Because the officers did not develop probable cause to suspect 

Trahey of DUI until nearly eighty minutes after the accident, the Commonwealth argues 

that there was no conceivable way for the officers to obtain a search warrant with enough 

time to obtain a satisfactory reading of Trahey’s BAC, i.e., “before hitting the two-hour 

window to preserve reliable evidence.” Id. at 18.
[J-64-2019] - 12

The Commonwealth disputes Trahey’s assertion that a breath test would have 

served law enforcement needs adequately, or that it must have made some separate 

showing of the necessity for a warrantless blood test. Although it concedes that the 

available evidence suggested that Trahey was under the influence of alcohol, the 

Commonwealth contends that the “police had a responsibility to obtain all relevant 

evidence of his intoxication, which may have included the use of other substances that 

caused side effects not as immediately apparent as alcohol.” Id. The Commonwealth 

emphasizes the McNeely Court’s holding that the Fourth Amendment requires officers to 

obtain a search warrant for a blood draw provided that they can do so “without significantly 

undermining the efficacy of the search.” Id. (quoting McNeely, 569 U.S. at 152). Where 

exigent circumstances create a delay that undermines the efficacy of the search, the 

Commonwealth observes, “a warrantless search is reasonable.” Id. It asserts, however, 

that “[t]here is no suggestion in McNeely, or any case cited by [Trahey], that police must 

also prove that they could not have performed a less accurate breathalyzer test” or that 

the Commonwealth must make “some showing of probable cause to suspect that a 

search will reveal the presence of an intoxicant other than alcohol.” Id. at 18-19.

“The greatest exigency in this case,” the Commonwealth argues, “was that each 

passing minute threatened the destruction of evidence” in Trahey’s bloodstream. Id. at 

20. The threat of that diminishing evidentiary value was, in the Commonwealth’s words, 

“exacerbated by constraints that delayed police from responding to the scene of the 

accident,” but which lay outside the control of the officers. Id. Thus, the Commonwealth 

concludes, the warrantless blood draw conducted in this case was justified by exigent 

circumstances, and that exigency was not one of the officers’ own making.
[J-64-2019] - 13

III.

Because Trahey prevailed before the suppression court, our scope of review 

permits us to “consider only the evidence of the defense and so much of the evidence for 

the Commonwealth as remains uncontradicted” in the record. Commonwealth v. Lukach,

195 A.3d 176, 183 (Pa. 2018) (quoting Commonwealth v. Mistler, 912 A.2d 1265, 1268-

69 (Pa 2006)). Trahey did not offer any evidence at the suppression hearing, however, 

and relied solely upon legal propositions relating to the constitutionality of the warrantless 

blood draw. Accordingly, we may consider all of the Commonwealth’s evidence in 

determining whether the suppression court’s findings of fact are supported by the record, 

in which case they are binding upon this Court. Id. By contrast, we review the court’s 

legal conclusions de novo. Commonwealth v. Brown, 996 A.2d 473, 476 (Pa. 2010).

As a preliminary matter, we note that, although the legal question before us is 

significantly informed by the Birchfield decision, the events at issue here preceded the 

issuance of the Court’s opinion in that case.7 Accordingly, we recognize that the officers 

in this matter had no reason to anticipate the subsequent change in the law. Moreover, 

in the context of criminal sentencing for DUI offenses, where Birchfield also has 

significantly altered the governing legal framework, we have held that the decision does 

not apply retroactively to collateral attacks on the legality of sentences that became final 

before Birchfield was decided. Commonwealth v. Olson, 218 A.3d 863 (Pa. 2019). 

Nonetheless, litigants generally are entitled to benefit from changes in the law that 

develop before their judgments of sentence become final, provided that “the issue in 

question is properly preserved at all stages of adjudication up to and including any direct 

appeal.” Commonwealth v. Cabeza, 469 A.2d 146, 148 (Pa. 1983); accord 

 

7 Trahey was arrested and subjected to a warrantless blood draw on September 4, 

2015. The Supreme Court of the United States decided Birchfield on June 23, 2016.
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Commonwealth v. Hays, 218 A.3d 1260 (Pa. 2019). Trahey indisputably preserved his 

challenge to the legality of the blood draw by filing, litigating, and prevailing on his 

suppression motion prior to trial. Accordingly, although the investigating officers were 

reasonably operating under an older understanding of the requirements of the Fourth 

Amendment, Trahey is entitled to a review conducted through the lens of the Supreme 

Court’s more recent pronouncements in this area.

A.

The Fourth Amendment provides:

The right of the people to be secure in their persons, houses, papers, and 

effects, against unreasonable searches and seizures, shall not be violated, 

and no Warrants shall issue, but upon probable cause, supported by Oath 

or affirmation, and particularly describing the place to be searched, and the 

persons or things to be seized.

U.S. CONST. amend IV.

Both breath tests and blood tests constitute “searches” within the meaning of the 

Fourth Amendment. See Skinner v. Ry. Labor Executives’ Assn., 489 U.S. 602, 616-17

(1989); Schmerber v. California, 384 U.S. 757, 767-68 (1966). Accordingly, conducting 

such a search without a warrant “is reasonable only if it falls within a recognized 

exception” to the warrant requirement. McNeely, 569 U.S. at 148 (citing United States v. 

Robinson, 414 U.S. 218, 224 (1973)). One such exception, as noted above, applies 

where “the exigencies of the situation make the needs of law enforcement so compelling 

that a warrantless search is objectively reasonable under the Fourth Amendment.” Id. at 

148-49 (quoting King, 563 U.S. at 460). Although an exigency may present itself in a 

variety of contexts, its defining trait is a “compelling need for official action and no time to 

secure a warrant.” Id. at 149 (quoting Michigan v. Tyler, 436 U.S. 499, 509 (1978)). Such 

a need may arise, for instance, “to prevent the imminent destruction of evidence.” Id.

(citing Cupp v. Murphy, 412 U.S. 291, 296 (1973); Ker v. California, 374 U.S. 23, 40-41 
[J-64-2019] - 15

(1963)). In evaluating the presence of an exigency, we consider the totality of the 

circumstances. Id. (citing Brigham City v. Stuart, 547 U.S. 398, 406 (2006)).

In this case, the Superior Court’s legal conclusion—that the warrantless blood 

draw was justified by exigent circumstances—rested upon the synthesis of two 

propositions. The first premise is that the anticipation of difficulty in obtaining and 

executing a search warrant prior to the expiration of the two-hour window set forth in the 

DUI statute, see, e.g., 75 Pa.C.S. § 3802(a)(2), the “optimal time period to obtain accurate 

blood testing evidence,” Trahey, 183 A.3d at 452, gives rise to an urgent need for 

warrantless testing. The second premise is that breath testing and blood testing are 

materially equivalent with regard to that antecedent justification, i.e., that once the urgent 

need for BAC testing is established, either type of test may be conducted without a search 

warrant. A review of McNeely, Birchfield, and, most recently, Mitchell, reveals error in 

this approach.

B.

In McNeely, the Court rejected the government’s argument that the natural 

dissipation of alcohol in a DUI suspect’s bloodstream constitutes a “per se exigency” that 

categorically justifies warrantless BAC testing. McNeely, 569 U.S. at 147. The Court 

relied upon its 1966 decision in Schmerber, where it held that an officer who arrested a 

DUI suspect at a hospital following an automobile accident lawfully could demand the 

suspect’s submission to a warrantless blood test because, due to the body’s natural 

metabolic processes, the officer “might reasonably have believed that he was confronted 

with an emergency, in which the delay necessary to obtain a warrant, under the 

circumstances, threatened the destruction of evidence.” Schmerber, 384 U.S. at 770 

(internal quotation marks omitted). The McNeely Court clarified that Schmerber does not 

stand for a per se rule in that regard, but in fact turned upon the individual facts and 
[J-64-2019] - 16

circumstances of the case, including the need to investigate the accident scene and to 

allow the suspect to be transported to a hospital for medical treatment, which left “no time 

to seek out a magistrate and secure a warrant.” McNeely, 569 U.S. at 151 (quoting 

Schmerber, 384 U.S. at 771).

Schmerber having failed to resolve the question of a per se rule, the McNeely Court 

addressed whether the state’s proposed approach otherwise could be justified under the 

exigent circumstances doctrine. The Court deemed such a rule inconsistent with the 

“careful case-by-case assessment of exigency” required by the totality of the 

circumstances test, id. at 152, and reasoned that adopting a per se rule would 

countenance a “considerable overgeneralization” of the governing standard. Id. at 153

(quoting Richards v. Wisconsin, 520 U.S. 385, 393 (1997)). The proposed per se rule 

further failed to “account for advances in the 47 years since Schmerber was decided that 

allow for the more expeditious processing of warrant applications, particularly in contexts 

like drunk-driving investigations where the evidence offered to establish probable cause 

is simple.” Id. at 154. Adopting the state’s per se rule, “would improperly ignore the 

current and future technological developments in warrant procedures, and might well 

diminish the incentive for jurisdictions ‘to pursue progressive approaches to warrant 

acquisition that preserve the protections afforded by the warrant while meeting the 

legitimate interests of law enforcement.’” Id. at 156 (quoting State v. Rodriguez, 156 P.3d 

771, 779 (Ut. 2007)).

The Court acknowledged that, technological developments notwithstanding, 

search warrant applications inevitably entail some amount of delay, and that certain 

factual scenarios may support findings of exigent circumstances arising from “delays from 

the warrant application process.” Id. at 156. The Court hypothesized, for example, that 

“practical problems” such as issues arising from “the procedures in place for obtaining a 
[J-64-2019] - 17

warrant or the availability of a magistrate judge, may affect whether the police can obtain 

a warrant in an expeditious way and therefore may establish an exigency that permits a 

warrantless search.” Id. at 164. However, such a determination, the Court held, requires 

a case-specific assessment of the circumstances.

“In short,” the McNeely Court held, “while the natural dissipation of alcohol in the 

blood may support a finding of exigency in a specific case, as it did in Schmerber, it does 

not do so categorically.” Id. Rather, “[w]hether a warrantless blood test of a drunk-driving 

suspect is reasonable must be determined case by case based on the totality of the 

circumstances.” Id. Stated differently, “where police officers can reasonably obtain a 

warrant before a blood sample can be drawn without significantly undermining the efficacy 

of the search, the Fourth Amendment mandates that they do so.” Id. at 152.8

McNeely having rejected the theory that the exigent circumstances doctrine 

provides a blanket justification for warrantless BAC testing, a question remained as to 

whether such testing could be justified categorically upon the basis of a different 

exception to the warrant requirement. In Birchfield, the Court provided an answer. A 

consolidation of three separate cases involving both breath and blood tests, the Birchfield 

decision focused upon the categorical authority provided by the search-incident-to-arrest 

doctrine.9 In a significant development of Fourth Amendment jurisprudence, the Birchfield

 

8 Portions of McNeely, principally those engaging the arguments of the responsive 

opinions, did not garner majority support, rendering McNeely a plurality decision in part. 

The foregoing quotations are taken only from the sections of the Court’s opinion that 

received majority support, and that thus bind this Court.

9 The question before the Birchfield Court was whether a DUI arrestee could be 

“convicted of a crime or otherwise penalized” for refusing to comply with warrantless 

breath or blood testing. Birchfield, 136 S.Ct. at 2172. However, the Court treated this 

question as a Fourth Amendment matter. The criminal law may not compel an individual 

to submit to an unconstitutional search, but “[i]f, on the other hand, such warrantless 

searches comport with the Fourth Amendment, it follows that a State may criminalize the 

refusal to comply with a demand to submit to the required testing, just as a State may 
[J-64-2019] - 18

Court introduced a new distinction in the law between breath and blood tests, based upon 

a comparative assessment of “the degree to which they intrude upon an individual’s 

privacy and the degree to which they are needed for the promotion of legitimate 

governmental interests.” Birchfield, 136 S.Ct. at 2176 (quoting Riley v. California, 573 

U.S. 373, 385 (2014)) (cleaned up).

A breath test, the Court reasoned, does not implicate “significant privacy 

concerns.” Id. (quoting Skinner, 489 U.S. at 626). It requires no piercing of one’s skin, 

entails minimal inconvenience or embarrassment, preserves no personal information 

aside from BAC, and collects nothing that humans do not dispel naturally by ordinary 

breathing. Id. at 2176-77. “Blood tests,” the Court reasoned, “are a different matter.” Id.

at 2178. Such tests involve piercing the skin and extracting material from a person’s body 

that is not naturally dispelled. Id. Blood tests further allow for the collection and 

preservation of a much broader array of information than a simple BAC reading. Id. 

Accordingly, the Birchfield Court concluded that blood testing has a much greater impact 

upon privacy interests than breath testing.

Turning to the governmental interests implicated, the Court readily acknowledged 

that both the state and federal governments have a “paramount interest” in preserving the 

safety of public highways, and that BAC testing of impaired drivers serves that interest. 

Id. (quoting Mackey v. Montrym, 443 U.S. 1, 17 (1979)). Rejecting the position of the 

dissenting Justices, who would except neither breath nor blood testing from the warrant 

requirement, the Court opined that, if every DUI arrest in the nation necessitated a search 

warrant application, “the courts would be swamped.” Id. at 2180. The Court pointed to 

 

make it a crime for a person to obstruct the execution of a valid search warrant.” Id. Thus, 

the question of the legality of the criminal penalty was answered “by considering whether 

the searches demanded in these cases were consistent with the Fourth Amendment.” Id.

at 2173.
[J-64-2019] - 19

North Dakota, from which two of the three cases before it originated, highlighted the 

relatively low number of judicial officers empowered to issue search warrants in that state, 

and concluded that demanding a warrant for every BAC test there would not be a “light 

burden.” Id. at 2181. Because the government’s interest in obtaining the evidence is 

substantial, and because the search-incident-to-arrest doctrine encompasses a 

recognition of the necessity of preventing the loss or “destruction” of evidence, id. at 2182 

(citing Chimel v. California, 395 U.S. 752, 763 (1969)), the Court held that “the Fourth 

Amendment permits warrantless breath tests incident to arrests for drunk driving.” Id. at 

2184. “The impact of breath tests on privacy is slight, and the need for BAC testing is 

great.” Id. “Blood tests,” by contrast, “are significantly more intrusive, and their 

reasonableness must be judged in light of the availability of the less invasive alternative 

of a breath test.” Id. The Court added that the government had “offered no satisfactory 

justification for demanding the more intrusive alternative without a warrant.” Id.

The Court noted that breath tests have been in common use for many years, that 

their results are admissible in court and widely credited by juries, and that no party 

disputed their “accuracy or utility.” Id. at 2184. “What, then,” the Court asked, “is the 

justification for warrantless blood tests?” Id. The Court considered and rejected a number 

of proposed justifications for warrantless blood testing, beginning with an observation that 

anticipated the arguments offered in the instant case. A blood test, the Court noted, can 

detect not only alcohol, “but also other substances that can impair a driver’s ability to 

operate a car safely.” Id. “A breath test cannot do this,” the Court acknowledged, “but 

police have other measures at their disposal when they have reason to believe that a 

motorist may be under the influence of some other substance (for example, if a breath 

test indicates that a clearly impaired motorist has little if any alcohol in his blood).” Id. 

Further, a blood test may be administered to uncooperative or unconscious individuals 
[J-64-2019] - 20

who cannot or will not comply with breath testing procedures, or who deliberately attempt 

to blow an insufficient breath sample. Id. at 2184-85. Despite these additional benefits 

that blood testing may offer under certain circumstances, the Court remained 

unpersuaded that these considerations justified a categorical exception to the warrant 

requirement. In such situations, a case-specific exigency may be established, or “a 

warrant for a blood test may be sought.” Id. at 2185.

Summarizing its reasoning, the Court held that, “[b]ecause breath tests are 

significantly less intrusive than blood tests and in most cases amply serve law 

enforcement interests, . . . a breath test, but not a blood test, may be administered as a 

search incident to a lawful arrest for drunk driving.” Id. Accordingly, breath tests, but not 

blood tests, are categorically excepted from the Fourth Amendment’s warrant 

requirement. Id.10

The Supreme Court revisited this subject most recently in Mitchell. A plurality 

decision, Mitchell addressed a “narrow but important category of cases: those in which 

the driver is unconscious and therefore cannot be given a breath test.” Mitchell, 139 S.Ct. 

at 2531 (plurality). Building upon McNeely and Birchfield, the Mitchell plurality again 

highlighted the compelling governmental interest in obtaining BAC evidence from 

impaired drivers. Id. at 2535-37. Although, under Birchfield, a breath test generally 

satisfies that interest, the Mitchell plurality observed that, “in the case of unconscious 

drivers, who cannot blow into a breathalyzer, blood tests are essential for achieving the 

compelling interests” of law enforcement. Id. at 2537. The question that the plurality 

 

10 The Birchfield Court further rejected the government’s alternative argument that 

the blood tests at issue could be justified upon the basis of a statutory “implied consent” 

provision, holding that “motorists cannot be deemed to have consented to submit to a 

blood test on pain of committing a criminal offense.” Birchfield, 136 S.Ct. at 2186. This 

theory is not at issue in the instant case.
[J-64-2019] - 21

framed was “whether this compelling need justifies a warrantless search” under the 

exigent circumstances doctrine. Id.

Under that doctrine, the plurality reasoned, a warrantless blood draw may be 

permissible when, in conjunction with the dissipation of BAC evidence, “some other factor 

creates pressing health, safety, or law enforcement needs that would take priority over a 

warrant application.” Id. The unconscious state of a motorist not only suggests a 

dangerous degree of intoxication, but “is itself a medical emergency.” Id. (emphasis in 

original). Further, many unconscious-driver cases will involve vehicular accidents, which 

“might give officers a slew of urgent tasks” such as ensuring prompt medical attention for 

other injured persons, providing first aid until medical personnel arrive, preserving 

evidence, or blocking or redirecting traffic around the accident scene. Id. at 2538. Where 

these “rival priorities” are present, officers may be required to delay a warrant application 

and thus the BAC test, “to the detriment of its evidentiary value and all the compelling 

interests served by BAC limits.” Id. Accordingly, where police officers have probable 

cause to believe that a suspect has committed a DUI offense, but the suspect’s 

unconscious state “requires him to be taken to the hospital or similar facility before police 

have a reasonable opportunity to administer a standard evidentiary breath test,” the 

officers “may almost always order a warrantless blood test to measure the driver’s BAC 

without offending the Fourth Amendment.” Id. at 2539.11

 

11 Justice Thomas concurred only in the judgment of Mitchell, reiterating his 

dissenting position in McNeely that warrantless BAC testing always should be permitted 

under a per se exigency theory, “regardless of whether the driver is conscious.” Mitchell, 

139 S.Ct. at 2539 (Thomas, J., concurring in the judgment). Because no single rationale 

in Mitchell commanded a majority on any point, “the holding of the Court may be viewed 

as that position taken by those Members who concurred in the judgment on the narrowest 

grounds.” City of Lakewood v. Plain Dealer Pub. Co., 486 U.S. 750, 764 n.9 (1988) 

(quoting Marks v. United States, 430 U.S. 188, 193 (1977)) (bracket omitted). Justice 

Thomas having advanced a broader rationale, the narrowest grounds supporting the 

judgment were those offered by the plurality. Accordingly, the holding of Mitchell, in the 
[J-64-2019] - 22

In light of these recent pronouncements, it is clear that the Supreme Court of the 

United States has signaled its preference for breath testing in order to avoid the 

undesirable consequence of BAC evidence dissipating as a result of the delays attending 

the search warrant application process. The Birchfield Court’s constitutional distinction 

between breath and blood testing is unmistakable, and the Mitchell plurality premised its 

legal conclusion upon the existence of a circumstance in which “a breath test is 

impossible.” Mitchell, 139 S.Ct. at 2531 (plurality). Indeed, the Mitchell plurality repeated 

this limitation of its holding no fewer than ten times throughout its opinion.12

C.

Returning to the instant case, as noted above, the Superior Court premised its 

finding of exigency upon the justifiable delay in police response to the accident scene, the 

number of AID officers on duty that evening, and Officer Shead’s testimony detailing the 

time frames involved in the search warrant application process in Philadelphia at the 

 

plurality’s words, is that where a “driver is unconscious and therefore cannot be given a 

breath test,” the “exigent-circumstances rule almost always permits a blood test without 

a warrant.” Mitchell, 139 S.Ct. at 2531. See also People v. Eubanks, __ N.E.3d __, 2019 

WL 6596704 at *13 n.6 (Ill. 2019) (concluding that the Mitchell plurality’s rationale 

represents the Court’s holding).

12 See Mitchell, 139 S.Ct. at 2531 (plurality) (“the driver is unconscious and therefore 

cannot be given a breath test”); id. (“When a breath test is impossible . . .”); id. at 2533 

(“unconsciousness also deprived officials of a reasonable opportunity to administer a 

breath test”); id. at 2534 (“no reasonable opportunity to give Mitchell a breath test using 

‘evidence-grade breath testing machinery”); id. (“when a driver’s unconsciousness (or 

stupor) eliminates any reasonable opportunity for [an evidence-grade] breath test”); id. at 

2535 (“And when a breath test is unavailable to advance those aims, a blood test 

becomes essential.”); id. at 2536 (“[W]hen a breath test is unavailable to promote those 

interests, ‘a blood draw becomes necessary.’”); id. at 2537 (“Thus, in the case of 

unconscious drivers, who cannot blow into a breathalyzer, blood tests are essential for 

achieving the compelling interests described above.”); id. (“[T]here clearly is a ‘compelling 

need’ for a blood test of drunk-driving suspects whose condition deprives officials of a 

reasonable opportunity to conduct a breath test.”); id. at 2539 (“the driver’s 

unconsciousness or stupor requires him to be taken to the hospital or similar facility before

police have a reasonable opportunity to administer a standard evidentiary breath test”).
[J-64-2019] - 23

time—seventy minutes on the low end, and upwards of three hours on the high end. 

Trahey, 183 A.3d at 452. After discussing Schmerber and McNeely, but not Birchfield’s 

distinction between breath and blood, the Superior Court concluded that the expected 

difficulty that the officers would have faced in obtaining a search warrant within two hours 

after the accident, the “optimal time period to obtain accurate blood testing evidence,” id., 

gave rise to a case-specific exigency justifying a warrantless blood draw.

The Superior Court’s analysis is problematic. First, as Trahey repeatedly 

emphasizes, the intermediate court paid no heed to the availability of a breath test in this 

case. Brief for Trahey at 28 (“Trahey was sitting right next to the machine and no warrant 

would be needed.”). Second, if an expected inability to obtain a search warrant within 

two hours is sufficient to establish an exigency for a warrantless blood draw, and given 

Officer Shead’s testimony that a warrant application alone may have taken over two hours

in Philadelphia at the time, the Superior Court’s reasoning would appear to permit a

determination that exigent circumstances existed automatically, perhaps for all DUI 

arrests in the City of Philadelphia. This is a conclusion plainly in tension with McNeely’s 

rejection of a per se exigency approach.

We are cognizant of the significance of the two-hour period following the accident. 

The officers’, Commonwealth’s, and Superior Court’s focus upon this time period derives 

from the DUI statute itself. For alcohol-related offenses based upon a suspect’s BAC, the 

statute requires proof of the suspect’s BAC “within two hours after the individual has 

driven, operated or been in actual physical control of the movement of the vehicle.” 75 

Pa.C.S. § 3802(a)(2), 3802(b), 3802(c); see also id. § 3802(e) (relating to minors), 3802(f) 

(relating to commercial or school vehicles).13 It is undoubtedly true that the 

 

13 Recently, in Commonwealth v. Starry, __ A.3d __, 2020 WL 355367 (Pa. 2020), 

this Court held that the DUI statute does not absolutely require BAC testing within two

hours, such that evidence of a suspect’s BAC obtained beyond the two-hour window 
[J-64-2019] - 24

Commonwealth has a significant interest in obtaining evidence of a suspect’s BAC within 

this time period. This time frame not only relates to a necessary element of certain DUI 

offenses, but it is, of course, well-understood that the alcohol in a suspect’s blood 

dissipates relatively rapidly through natural metabolic processes, thus diminishing the 

evidentiary value of a belated test. See generally McNeely, supra. We are further aware 

of, and sympathetic to, the potential difficulties that an officer could face in seeking to 

obtain and execute a search warrant within the two-hour window provided by the statute.14 

These same concerns were a driving factor in the Birchfield Court’s decision to articulate

a categorical exception to the warrant requirement for a powerful evidentiary tool: a 

breath test.

Simply put, any concern about the time necessary to obtain a search warrant in 

this context is significantly ameliorated, if not wholly extinguished, by the fact that no 

search warrant is necessary under the Fourth Amendment to demand that a DUI arrestee

perform a breath test. Such a test is a valid search incident to a lawful arrest for DUI, and 

the arrestee has “no right to refuse it.” Birchfield, 136 S.Ct. at 2186.

 

nonetheless may be “related back” so as to develop circumstantial evidence of the 

suspect’s BAC during that timeframe.

14 Although the Commonwealth does not offer such a theory in this case, we note 

that the DUI statute provides an exception to its “two-hour rule.” 75 Pa.C.S. § 3802(g). 

The exception states that, where BAC is an element of a DUI offense, and BAC evidence 

is obtained in excess of two hours after the suspect’s last operation of the vehicle, the 

BAC nonetheless will suffice if the Commonwealth “shows good cause explaining why 

the chemical test sample could not be obtained within two hours” and “establishes that 

the individual did not imbibe any alcohol or utilize a controlled substance between the 

time the individual was arrested and the time the sample was obtained.” Id. § 3802(g)(1)-

(2); but see Starry, __ A.3d at __; 2020 WL 355367, at *6-7. Rather than allowing the 

statutory two-hour rule to control the constitutional determination of exigent 

circumstances, it would be more sensible to suggest that a delay occasioned by the 

process for obtaining a search warrant for a blood draw constitutes “good cause” for 

exceeding the statute’s two-hour window. We leave open such a theory for a future case.
[J-64-2019] - 25

Unsatisfied with the categorical permissibility of warrantless breath testing, the 

Commonwealth asserts that Trahey has cited no precedent suggesting that the need for 

a warrantless blood test must be bolstered by a showing that the police officers “could not 

have performed a less accurate breathalyzer test.” Brief for Commonwealth at 18. To 

the contrary, the Birchfield Court clearly stated that blood tests “are significantly more 

intrusive, and their reasonableness must be judged in light of the availability of the less 

invasive alternative of a breath test.” Birchfield, 136 S.Ct. at 2184. As for the 

Commonwealth’s contention that breath tests are less accurate than blood tests—an 

assertion for which it provides no empirical support—its grievance must be directed to the 

Birchfield Court itself, which highlighted the commonality, admissibility, and credibility of

breath tests, and held, as a matter of federal constitutional law, that such tests “in most 

cases amply serve law enforcement interests.” Id. at 2185.

This brings us to the question, much like the one that the Birchfield Court asked, 

of what law enforcement interest could not be served by a breath test in this case. The 

Commonwealth asserts that the investigating officers had not only a prerogative, but a 

“responsibility,” to obtain all evidence of potential intoxication, including any controlled

substances in Trahey’s bloodstream. Brief for Commonwealth at 18. The 

Commonwealth further argues that it need not show discrete probable cause with respect 

to controlled substances. Id. at 19. The Commonwealth’s argument echoes Officer 

Shead’s testimony explaining that the officers chose a blood test in this case because “a 

Breathalyzer only shows someone’s blood alcohol concentration,” and does not reveal 

whether there are “other intoxicants” in the suspect’s system, i.e., controlled substances. 

N.T. at 128.

The Commonwealth does not suggest, however, that the same concerns regarding 

the rapid dissipation of alcohol in the bloodstream apply to controlled substances. The 
[J-64-2019] - 26

timing constraints that animated the decisions in McNeely, Birchfield, and Mitchell all 

related to the evanescent nature of alcohol in a suspect’s breath or blood, which 

deteriorates in a matter of hours. None of those decisions suggested that controlled 

substances raise the same concerns. Indeed, the DUI statute facially reflects the 

diminished urgency of testing for controlled substances, inasmuch as its two-hour rule

does not apply to the offense of driving under the influence of controlled substances. See 

75 Pa.C.S. § 3802(d); Commonwealth v. Wilson, 101 A.3d 1151, 1156 (Pa. Super. 2014) 

(“[W]e find that the absence of any such time requirement in subsection 3802(d) [is] 

persuasive that the legislature did not envision a time limit on testing for the presence of 

controlled substances after driving.”). Moreover, there is no range of permissible 

concentrations of prohibited substances in a motorist’s bloodstream; rather, “any amount” 

of such a substance in a motorist’s system constitutes an offense. 75 Pa.C.S. 

§ 3802(d)(1). This further establishes the absence of a need for testing within two hours. 

Accordingly, even if a search warrant application were to take the full three hours that 

Officer Shead posited that it may, there is minimal risk that evidence of controlled 

substances in the suspect’s blood would reduce to a completely undetectable level within 

that time.

In effect, the Commonwealth asks this Court to conclude that, because there was 

an urgent need to test for Trahey’s blood alcohol concentration within two hours—a need 

that could be satisfied with a breath test—there accordingly were exigent circumstances 

justifying a warrantless blood test for controlled substances, a category of evidence that 

does not require testing within two hours.15 We cannot endorse this conclusion. Exigent 

 

15 Further, this Court’s recent decision in Starry, see supra n.13, undercuts the 

Commonwealth’s assertion of exigency as it relates to the DUI statute’s two-hour window. 

The Starry Majority made clear that its relation-back rationale and the good-cause 

exception are “statutory alternatives made available to the prosecution.” Starry, __ A.3d 

at __; 2020 WL 355367, at *6. Accordingly, pursuant to Starry, there was no absolute 
[J-64-2019] - 27

circumstances are defined by a “compelling need for official action and no time to secure 

a warrant.” McNeely, 569 U.S. at 149 (quoting Tyler, 436 U.S. at 509)). With regard to 

alcohol, there is no need for a warrantless blood test because the “less invasive 

alternative of a breath test” adequately serves the government’s interest in obtaining the 

evidence sought. Birchfield, 136 S.Ct. at 2184. With regard to controlled substances, a 

blood test may be necessary, but there is no pressing need to conduct the test within a 

specified time, and thus no exigency.

16

 

requirement that the investigating officers must have obtained evidence of Trahey’s BAC 

within two hours after his last operation of a vehicle. Rather, upon the execution of a BAC

test outside the statutory two-hour window, and even absent a showing of good cause for 

delay, Trahey’s BAC could have been related back to the relevant timeframe, thus 

diminishing the need for exceptional haste in order to satisfy a rigid timeframe.

16 The Concurrence expresses concern that we have relied too heavily upon the 

availability of a breath test in assessing the need for a warrantless blood test, opining that 

“the two tests are separate and distinct, and access to a breath test does not necessarily 

affect a warrant application or the applicability of an exception to the warrant requirement 

for obtaining a blood test.” Conc. Op. at 1 (Mundy, J.). This position is flatly contradicted 

by the language of Birchfield, which the Concurrence quotes, but does not reconcile: 

“Blood tests are significantly more intrusive, and their reasonableness must be judged in 

light of the availability of the less invasive alternative of a breath test.” Birchfield, 136 

S.Ct. at 2184. 

Certainly, the Concurrence is correct that breath tests and blood tests are 

“separate and distinct.” Conc. Op. at 1 (Mundy, J.). The Birchfield Court’s rationale was 

expressly comparative, viewing the tests in light of “the degree to which they intrude upon 

an individual’s privacy and the degree to which they are needed for the promotion of 

legitimate governmental interests.” Birchfield, 136 S.Ct. at 2176 (quoting Riley, 573 U.S.

at 385 (cleaned up)). The Court unmistakably premised its legal conclusion upon the 

much greater degree of invasion into protected privacy interests that attends blood testing 

as compared to breath testing, the latter of which, with regard to BAC detection, is 

“significantly less intrusive” and “in most cases amply serve[s] law enforcement interests.” 

Id. at 2185. This conclusion is markedly amplified by the Mitchell plurality’s muchrepeated emphasis that its exigency determination was premised upon the unavailability 

of breath testing in the unconscious-driver scenario. See supra at 21-22 & n.12. Indeed, 

the Concurrence’s suggestion that the availability of one type of test does not impact the 

permissibility of the other is further contradicted by Birchfield, inasmuch as the Court 

suggested that police officers may need to conduct a blood test “when they have reason 

to believe that a motorist may be under the influence of some other substance (for 
[J-64-2019] - 28

As the suppression court concluded, “[t]his is a case where a Breathalyzer could 

have been taken.” N.T. at 181. Trahey was conscious and sitting in the same room as 

an Intoxilyzer 8000 breath-testing machine. Id. at 23. There was no stated indication that 

Trahey was under the influence of a controlled substance, but probable cause to suspect 

non-alcoholic intoxication could have been established if, among any number of potential 

circumstances, a breath test revealed that alcohol would not explain the degree of 

Trahey’s apparent intoxication. See Birchfield, 136 S.Ct. at 2184. Had the investigating 

officers developed probable cause to suspect the presence of controlled substances in 

Trahey’s blood, they could have obtained a search warrant for a blood draw subject to no 

timing limitations.

The Superior Court was correct that the exigency analysis is an objective one. 

Trahey, 183 A.3d at 451. However, even disregarding the officers’ subjective motivations,

or their candid acknowledgment that they would have obtained a search warrant if they 

thought it necessary, see N.T. at 127-28, there was no time-sensitive need to conduct a 

 

example, if a breath test indicates that a clearly impaired motorist has little if any alcohol 

in his blood).” Birchfield, 136 S.Ct. at 2184. Thus, Birchfield reasoned that not only does 

the availability of a breath test impact the assessment of the need for a blood test, but the 

result of a breath test may as well.

Although the Concurrence highlights that Birchfield did not hold that there can 

never be exigent circumstances supporting a warrantless blood draw, Conc. Op. at 2 

(Mundy, J.), nor do we so hold. Case-specific showings of exigency under the totality of 

the circumstances are always available under the Fourth Amendment. But the exigent 

circumstances doctrine requires the demonstration of a “compelling need for official 

action” and “no time to secure a warrant.” McNeely, 569 U.S. at 149 (quoting Tyler, 436 

U.S. at 509). By weighing the need to obtain a blood sample under the circumstances of 

this DUI investigation against the evidence to which the search was directed and for which 

probable cause was obtained, and by viewing that need in light of the less invasive means 

available to effectuate the search, we have not erred by any means. We have simply 

applied the reasoning of Birchfield and Mitchell, and assessed the “reasonableness” of a 

“significantly more intrusive” warrantless blood draw “in light of the availability of the less 

invasive alternative of a breath test.” Birchfield, 136 S.Ct. at 2184.
[J-64-2019] - 29

warrantless blood test under the circumstances of this case. Accordingly, the Superior 

Court’s conclusion that the test was justified by exigent circumstances was drawn in error.

The order of the Superior Court is reversed, and the matter is remanded for further 

proceedings consistent with this Opinion.

Justices Baer, Todd, Donohue and Dougherty join the opinion.

Justice Mundy files a concurring opinion in which Chief Justice Saylor joins.