Court Opinion

ID: 6989
Source: CourtListenerOpinion
Date Created: 2010-04-25 05:23:40+00
Date Added: 2024-06-11T14:54:50.252513
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UNITED STATES COURT OF APPEALS
                          For the Fifth Circuit

                               No. 94-40159

                       UNITED STATES OF AMERICA,

                                                    Plaintiff-Appellant,

                                   VERSUS

                        ROHN MARTIN ISHMAEL and
                        DEBRA K. ISHMAEL,

                                                   Defendants-Appellees.

              Appeal from the United States District Court
                    For the Eastern District of Texas
                             (March 15, 1995)

Before REYNALDO R. GARZA, DeMOSS, and BENAVIDES, Circuit Judges.

DeMOSS, Circuit Judge:

       Based on the readings from a thermal imager, along with other

circumstantial evidence, federal law enforcement officers obtained

a warrant to search the premises of Rohn Martin Ishmael and his

wife, Debra K. Ishmael.        The officers executed the warrant and

discovered some firearms and 770 marijuana plants.           After being

indicted, the Ishmaels moved to suppress the evidence on the ground

that    the    warrantless   use    of   the    thermal   imager   was   a

constitutionally proscribed search. The district court granted the

Ishmaels' motion to suppress.       We now reverse.
                                        I.

     The   warrant     in   this   case      was   based   upon   the   following

information:    In the late summer of 1992, a confidential source

informed Paul Black, a Drug Enforcement Administration ("DEA")

officer, that he/she had delivered numerous truck loads of concrete

re-mix to the Ishmaels' secluded, rural property in Nacogdoches

County,    Texas.    The    Ishmaels,     according    to   the   source,    took

inordinate measures to conceal the need for the concrete.                    Rohn

Ishmael, for example, would manually mix the concrete near the

source's truck and then drive the concrete to another location on

the property.       His suspicions aroused, Black entered the property

and saw two mobile homes and a trailer.               Black, however, did not

witness any illegal activity.

     In August 1993, Black resumed his investigation. He and three

other officers returned to the property and followed a roughly

built road from the front of the property to a steep embankment

where a large hole had been made.             They observed around 60 empty

bags of cement, a dump truck and a concrete re-mixer parked near

the hole. The next day, Black investigated Rohn Ishmael's criminal

record and found at least four separate marijuana-related incidents

dating back to 1974, several of which involved the cultivation of

marijuana. Black, along with other DEA officers, then surveyed the

Ishmaels' property by air.         They observed a mobile home and a large

steel building, separated by about 200 to 300 yards.                    The steel

building stood next to a 2-acre pond.              Black entered the property

on foot two more times.       He discovered that the Ishmaels had built

                                        2
a structure beneath the steel building. The substructure was wired

for electricity and was being fed water from the nearby pond by way

of exposed rubber tubes and a water pump.                          The substructure also

had an exhaust fan, which Black noticed was continuously running.

Black also observed a nearby pallet containing 100 5-gallon plastic

buckets.

     Suspecting that the Ishmaels were cultivating marijuana in the

structure beneath the steel building, the DEA boarded a helicopter

with a thermal imager and flew over the Ishmaels' property at

approximately      500     to    1000       feet.        A    thermal    imager    detects

differences in surface temperature of targeted objects and displays

those differences through a viewfinder in varying shades of white

and gray.       In other words, a warm object will appear white on the

device's viewfinder, whereas a cool object will appear gray.                            The

device can record its readings on a standard videocassette.                             The

DEA's recording of the Ishmaels' property showed that, although the

water entering the substructure was noticeably cool, the water

exiting    it    was    emitting       a    substantial        amount    of    heat.    The

recording additionally showed that the ground adjacent to the

substructure was much warmer than the ground further from the

substructure.

     Black then subpoenaed the Ishmaels' telephone records.                            The

records indicated that the Ishmaels had made numerous calls to

various horticulture shops, two of which appeared on a narcotics

intelligence      computer       base       as       suppliers     for   other   marijuana

cultivators.           Black    also       subpoenaed        the   Ishmaels'     electrical

                                                 3
utility records.      The records showed that the substructure's power

usage was extremely high and far exceeded the mobile home's power

usage.

      In September 1993, Black and several other officers again

entered the Ishmaels' property on foot.            Using a hand-held thermal

imager, the officers canvassed the perimeter of the steel building

but never entered it.         The officers made essentially the same

findings;     an   unusual   amount   of    heat   was     emanating   from   the

substructure and the ground adjacent to it.                Black displayed his

recordings to two DEA thermographers, both of whom concluded that

the Ishmaels were illegally cultivating marijuana in the steel

building's substructure.          The DEA then used the thermal imager's

readings, along with the wealth of information gathered by Black,

to   obtain    a   warrant   to    search   the    steel    building   and    its

substructure on the Ishmaels' property.            The officers executed the

warrant two days later and uncovered 770 marijuana plants and

several firearms.        After being indicted in October 1993, the

Ishmaels moved to suppress the evidence obtained pursuant to the

search warrant.       They argued that the readings from the thermal

imager constituted an unconstitutional search and that, without

those readings, the DEA did not have probable cause to obtain a

warrant.

      The district court granted the motion to suppress in January

1994.    See United States v. Ishmael, 843 F. Supp. 205 (E.D. Tex.

1994). The court employed a burden-shifting analysis. The burden,

it observed, initiated with the Ishmaels to demonstrate that they

                                       4
had a reasonable expectation of privacy. The court concluded that,

although the steel structure was outside the curtilage of the home,

the Ishmaels nonetheless had exhibited a reasonable expectation of

privacy. Id. at 209-12. Specifically, it noted that "the Ishmaels

had a reasonable expectation that their effects, associated with

the secreted metal building and the business being conducted there,

were safe from [g]overnmental surveillance." Id. at 211. Pointing

to Florida v. Riley, 488 U.S. 445 (1989), and California v.

Ciraolo, 476 U.S. 207 (1986), the government argued that the

Ishmaels did not have a reasonable expectation of privacy from the

DEA's air surveillances.      The court rejected the government's

argument, reasoning that those cases were limited exclusively to

naked-eye observations.    Id. at 211-12.

     According to the district court, the burden then shifted to

the government to prove that its search fell within one of the

several recognized exceptions to the warrant requirement.      The

government, relying on Dow Chemical Company v. United States, 476
U.S. 227 (1986), argued below that the heat emissions were in

"plain view."   The court rejected the "plain view" argument on the

ground that the heat emissions would not be in plain view without

the use of "sophisticated technology," namely the thermal imager.

Id. at 212.     Alternatively, the government analogized the heat

emissions to curb-side garbage (as in California v. Greenwood, 486
U.S. 35 (1988)) and the scent of cocaine emanating from luggage (as

                                  5
in United States v. Place, 462 U.S. 696 (1983)): because each has

been    effectively    abandoned,       the   defendant   no   longer    has   a

subjective expectation of privacy in its concealment.               The court

rejected the government's analogies on the ground that the relative

sophistication of the thermal imager poses a greater intrusion than

officers manually rummaging through abandoned garbage or a trained

police dog alerting to a suitcase carrying contraband.             Id. at 212-

13.

       Having found that the use of the thermal imager constituted a

search proscribed by the Fourth Amendment, the court proceeded to

determine whether the remaining evidence amounted to probable

cause.     The court noted that the DEA had no direct evidence of

illegal activity taking place on the Ishmaels' property.                Id. at

213-14.     The court stated, "The evidence of their activity was

consistent    with    developing    a   new   patented    strain   of   African

violets, and innumerable other perfectly legal activities." Id. at

214.     On this basis, the court concluded that a judge would not

find that probable cause existed for issuing a warrant, and it

therefore granted the Ishmaels' motion to suppress. The government

now appeals the district court's holdings that the warrantless use

of the thermal imager was unconstitutional and that, absent its

readings, probable cause did not exist for the issuance of the

warrant.

                                        II.

                                        A.

                                         6
     In   reviewing    a   district   court's   ruling   on   a   motion   to

suppress, we review the court's conclusions of law de novo and its

findings of fact for clear error.          United States v. Cardenas, 9
F.3d 1139, 1147 (5th Cir. 1993); United States v. Sanders, 994 F.2d
200, 202-03 (5th Cir. 1993).       Furthermore, we view the evidence in

a light most favorable to the prevailing party, United States v.

Piaget, 915 F.2d 138, 140 (5th Cir. 1990), which in this case is

the Ishmaels.

                                      B.

     The warrantless use of thermal imagers by the police has

spawned a fair amount of search and seizure jurisprudence over the

last several years.1       Though the Fifth Circuit has yet to squarely

address this issue,2 three of our sister circuits have, and each

    1
      See United States v. Myers, ___ F.3d ___, 1995 WL 38118 (7th
Cir. 1995); United States v. Robertson, 39 F.3d 891 (8th Cir.
1994); United States v. Kyllo, 37 F.3d 526 (9th Cir. 1994); United
States v. Ford, 34 F.3d 992 (11th Cir. 1994); United States v.
Pinson, 24 F.3d 1056 (8th Cir. 1994); United States v. Olson, 21
F.3d 847 (8th Cir. 1994); United States v. Deaner, 1 F.3d 192 (3d
1993); United States v. Feeney, 984 F.2d 1053 (9th Cir. 1993);
State v. Young, 867 P.2d 593 (Wash. 1994); United States v. Field,
855 F. Supp. 1518 (W.D. Wis. 1994); United States v. Domitrovich,
852 F. Supp. 1460 (E.D. Wash. 1994); United States v. Porco, 842 F.
Supp. 1393 (D. Wyo. 1994); United States v. Deaner, 1992 WL 209966
(M.D. Pa. 1992); United States v. Kyllo, 809 F. Supp. 787 (D. Or.
1992), vacated on other grounds, 37 F.3d 526 (9th Cir. 1994);
United States v. Penny-Feeney, 773 F. Supp. 220 (D. Haw. 1991),
aff'd on other grounds, 984 F.2d 1053 (9th Cir. 1993); see also
Lisa J. Steele, Waste Heat and Garbage: The Legalization of
Warrantless Infrared Searches, 29 CRIM. L. BULL. 19 (1993).
    2
      In United States v. Broussard, 987 F.2d 215 (5th Cir. 1993),
the defendant moved to suppress certain evidence on the ground that
the affidavit the government submitted in requesting a warrant was
insufficiently detailed. In affirming the district court's denial
of the motion, we noted that, to the extent that the affidavit was
inadequate, the warrant was nonetheless valid because the
government had supplied findings from a thermal imaging device.

                                      7
has concluded that such use is not a "search" proscribed by the

Fourth Amendment.    United States v. Myers, 1995 WL 38118, at *2-*3

(7th Cir. 1995); United States v. Ford, 34 F.3d 992, 995-97 (11th

Cir. 1994); United States v. Pinson, 24 F.3d 1056, 1058-59 (8th

Cir. 1994).     We now hold that the warrantless use of a thermal

imager in an "open field" does not violate the Fourth Amendment.

                                     1.

     The Fourth Amendment provides in part: "The right of the

people to be secure in their persons, houses, papers, and effects,

against unreasonable searches and seizures, shall not be violated."

U.S. CONST. amend. IV.      As in any Fourth Amendment surveillance

case, our analysis begins with Katz v. United States, 389 U.S. 347

(1967).     The Supreme Court in Katz enunciated its two-prong test

for determining whether a warrantless search violated a defendant's

legitimate    expectation   of   privacy:    the    defendant    must    have

exhibited a subjective expectation of privacy, and that expectation

must be one society is prepared to recognize as reasonable.             Id. at

361 (Harlan, J., concurring); see also Ciraolo, 476 U.S. at 211

(majority opinion). With regard to the first prong, the government

maintains    that   the   Ishmaels   did    not    exhibit   a   subjective

expectation of privacy because they made no effort to conceal the

heat emanating from the building. In fact, the Ishmaels encouraged

emission of the heat by installing an exhaust fan that operated

Id. at 222.      Because the defendant did not challenge the
constitutionality of the warrantless use of the device, we did not
address the issue. See also United States v. Zimmer, 14 F.3d 286,
288 (6th Cir. 1994).

                                     8
continuously.   Thus, the government argues, the Ishmaels clearly

failed Katz' first prong because "[w]hat a person knowingly exposes

to the public, even in his home or office, is not a subject of

Fourth   Amendment   protection."       Katz, 389 U.S.   at   351.     The

Ishmaels, in response, contend that the government's argument is

somewhat specious; while the substructure admittedly was emitting

heat, that emission was not a deliberate act.          The law of physics,

and not the Ishmaels' failure to contain, controlled the emission

of heat from the substructure.           The Ishmaels argue that the

government's "heat waste" analogy therefore is a bad one because

one who expects his garbage to remain private can refrain from

leaving it at the curb, whereas one who expects his heat waste to

go undetected can only hope the police is not presently scanning

his property with a thermal imager.

     In cases involving very similar facts, other courts have

readily accepted the heat waste analogy in concluding that the

defendants' have failed to satisfy Katz' first prong.             See, e.g.,

Myers, ___ F.3d at ___; Ford, 34 F.3d at 995; Domitrovich, 852 F.

Supp. at 1472-73; Penny-Feeney, 773 F. Supp. at 225-26.                  But a

cursory review of Katz itself demonstrates that the first prong

probably is not as restrictive as these courts have interpreted it

to be.    In Katz, the government, without a warrant, attached a

recording device to the exterior of a telephone booth that the

defendant used to illegally transmit gambling information.                 The

defendant argued that the government's warrantless eavesdropping

was proscribed by the Fourth Amendment, and the Supreme Court

                                    9
agreed. Though the defendant in Katz did not take every precaution

against electronic eavesdropping, the Court nonetheless concluded

that he had exhibited a subjective expectation of privacy.                     Katz,
389 U.S.    at   353    (the   government's       warrantless        eavesdropping

"violated the privacy upon which [the defendant] justifiably relied

while using the telephone booth") (majority opinion). Likewise, in

Ciraolo, the defendant was cultivating marijuana in his backyard,

which was enclosed by a six-foot outer fence and a ten-foot inner

fence.    Because the fences obstructed its view from ground level,

the police flew over the defendant's property at 1,000 feet and

observed the marijuana patch.          Though it ultimately concluded that

the search was constitutional, the Court initially concluded that

the defendant "[c]learly . . . ha[d] met the test of manifesting

his own subjective intent and desire to maintain privacy as to his

unlawful agricultural pursuits."                 Ciraolo, 476 U.S. at 211; see

also Riley, 488 U.S. at 449 ("We recognized [in Ciraolo] . . . that

the occupant had a subjective expectation of privacy.                      We held,

however, that such an expectation was not reasonable.").3

      Thus,    unless      we    intend     to     render    Katz'     first   prong

meaningless,       we    must   conclude    that    the     Ishmaels    exhibited   a

      3
     Riley is further proof that a dweller need not guard against
every possibility of detection in order to satisfy Katz' first
prong.   The defendant in Riley was cultivating marijuana in a
greenhouse that was missing several corrugated roofing panels.
Flying over the greenhouse in a helicopter at 400 feet, the police
observed marijuana through an opening in the roof. The Court found
that the defendant "no doubt intended and expected that his
greenhouse would not be open to public inspection." Riley, 488
U.S. at 450.   But concluding that Ciraolo was controlling, the
Court held that the search was nonetheless reasonable.

                                           10
subjective    expectation     that   their   hydroponic     laboratory   would

remain private.       See Smith v. Maryland, 442 U.S. 735, 740 n.5

(1979) ("[s]ituations can be imagined, of course, in which Katz'

two-pronged inquiry would provide an inadequate index of Fourth

Amendment protection").4       Though the Ishmaels did not -- indeed,

could not -- take every precaution against the detection of the

hydroponic laboratory, the balance of the evidence demonstrates

that the Ishmaels exhibited a subjective expectation of privacy.

Rohn Ishmael, for example, constructed the laboratory in great

secrecy.     In addition, it was built as a basement to a steel

building that was not visible from a public road.               We therefore

conclude that the Ishmaels have satisfied Katz' first prong.

                                      2.

        We now must address whether the government's intrusion on the

Ishmaels' subjective expectation of privacy with a thermal imager

is a reasonable one.    Oliver v. United States, 466 U.S. 170, 182-83

(1984) ("the correct inquiry is whether the government's intrusion

infringes upon the personal and societal values protected by the

Fourth Amendment").     It is at this point in the analysis that the

use of technology, and its degree of sophistication, becomes an

issue, because more sophisticated forms of technology increase the

likelihood     that   their    warrantless     use   will     constitute   an

    4
     See also 1 WAYNE R. LAFAVE, SEARCH AND SEIZURE § 2.1(c), at 308-310
(2d ed. 1987) (generally arguing that courts should avoid the
contemplation of unreasonable hypotheticals when applying the first
Katz prong); David H. Steinberg, Constructing Homes for the
Homeless? Searching for a Fourth Amendment Standard, 41 DUKE L.J.
1508, 1516-20 (1992).

                                      11
unreasonable   intrusion.      As       the   Supreme   Court   once      stated,

"surveillance of private property by using highly sophisticated

surveillance equipment not generally available to the public . . .

might be constitutionally proscribed absent a warrant."                       Dow

Chemical, 476 U.S. at 238.

     Dow Chemical provides useful guidance for search and seizure

cases involving surveillance technology.            There, the Environmental

Protection    Agency,    without    a    warrant,     had   flown   over   Dow's

industrial plant with a precise mapping camera.               Dow argued that

the use of the camera was an unconstitutional search.               The Supreme

Court disagreed, reasoning that the government is not foreclosed

from using technology to enhance its surveillances, provided that

that technology does not reveal "intimate details."                 Id. at 238.

The Court was satisfied that the camera did not reveal such

"details" because it was not "some unique sensory device that, for

example,   could   penetrate   the      walls    of   buildings     and    record

conversations in Dow's plants, offices, or laboratories, but rather

a conventional, albeit precise, commercial camera commonly used in

mapmaking."    Id. at 238.     Similarly, in United States v. Knotts,

460 U.S. 276 (1983), the police surveilled the defendant by means

of an electronic beeper attached to the interior of a five-gallon

chloroform drum.        Relying on the beeper's signals, the police

eventually uncovered the drum just outside the residence of one of

the defendants.    The defendant who owned the residence insisted

that the warrantless use of the beeper was unconstitutional because

it violated the sanctity of his home.           The Supreme Court, however,

                                        12
held that the surveillance was not an unreasonable search because

"there is no indication that the beeper was used in any way to

reveal information as to the movement of the drum within the

cabin."     Id. at 285; see also Place, 462 U.S. at 706-07 (specially

trained canine sniffing luggage is not an unconstitutional search

because it is a "limited disclosure" and involves no "embarrassment

and inconvenience"); Smith, 442 U.S. at 741-46 (pen register, which

discloses only the telephone numbers that have been dialed and not

the content of communications, is not an unconstitutional search);

United States v. Lee, 274 U.S. 559, 563 (1927) (searchlight that

uncovered contraband from a distance was not an unconstitutional

search).      Thus, the mere fact that the police have employed

relatively sophisticated forms of technological surveillance does

not render the surveillance unconstitutional.5               While technology

certainly gives law enforcement a leg up on crime, the Supreme

Court       has      "never      equated        police     efficiency          with

unconstitutionality."          Knotts, 460 U.S. at 284.              The crucial

inquiry, as in any search and seizure analysis, is whether the

technology reveals "intimate details."             Dow Chemical, 476 U.S. at

238.

       A thermal imager, according to the government, is no more

intrusive     than    the     other   animate     and    inanimate     means    of

        5
      "Nothing in the Fourth Amendment prohibited the police from
augmenting the sensory faculties bestowed upon them at birth with
such enhancement as science and technology afforded them in this
case." Knotts, 460 U.S. at 282. "The Supreme Court has repeatedly
held that the fact that a surveillance device allowed for super- or
extra-sensory perception is not fatal to a Katz analysis." Ford,
34 F.3d at 997.

                                       13
surveillance that the Supreme Court has concluded does not offend

the Fourth Amendment.         That is, like the trained canine in Place or

the precise mapping camera in Dow Chemical, a thermal imager is an

acceptable     surveillance         technique       because    it    does    not   reveal

intimate details within the structure being scanned.                        Instead, the

government argues, the device assesses only heat differentials in

objects and therefore poses no threat to the privacy concerns that

the Fourth Amendment is intended to protect. The Ishmaels contend,

however, that a thermal imager is the functional equivalent of an

X-ray    machine     in    that    it    allows     officers    to    "see"     within    a

structure     what    it    otherwise        cannot    see    with   the     naked   eye.

Specifically, they argue, a thermal imager measures heat that is

generated within a structure and, to that extent, constitutes an

unreasonable intrusion on one's Fourth Amendment privacy.                              The

Ishmaels, echoing the district court below, see Ishmael, 843 F.

Supp.    at   212,    argue       that   a   thermal    imager       is   the   type     of

"sophisticated technology" that the Court in Dow Chemical warned

law enforcement officials not to use without a warrant.

     The Ishmaels overstate the device's capabilities.                        The device

"does not intrude in any way into the privacy and sanctity of a

home."    Myers, ___ F.3d at ___.                 It "is a passive, non-intrusive

instrument" in that "[i]t does not send any beams or rays into the

area on which it is fixed or in any way penetrate structures within

that area."        Penny-Feeney, 773 F. Supp. at 223.                     As the Eighth

Circuit recently noted, "[t]he detection of the heat waste [is] not

an intrusion into the home; no intimate details of the home [are]

                                             14
observed, and there [is] no intrusion upon the privacy of the

individuals within."    Pinson, 24 F.3d at 1059.6      The device, in

other words, poses no greater intrusion on one's privacy than a

precise mapping camera, an electronic beeper, or a pen register.

     The manner in which a thermal imager was used in this case is

equally   significant   in   assessing   the   reasonableness   of   the

intrusion. When the DEA performed its pre-dawn thermal readings in

this case, the officers never physically invaded the Ishmael's

residential or commercial curtilage. See Dow Chemical, 476 U.S. at

237 ("[a]ny actual physical entry by EPA into any enclosed area

would raise significantly different questions").         The district

court below characterized the steel building as a "business," see

Ishmael, 843 F. Supp. at 210, and recognizing that we can review

the court's factual finding only for clear error, we will not

disturb the court's finding.7    But the court erred as a matter of

law when it stated the following: "to say that the government could

    6
     The Ishmaels also overstate its accessibility, which also is
a significant consideration. See Dow Chemical, 476 U.S. at 238.
As the district court in Deaner stated:
     The technology employed is "off the shelf," having been in
     general use for fifteen years. The device is utilized by many
     businesses for a variety of purposes, including the detection
     of roof leaks, steam pipe leaks, cracks in high voltage
     transmission lines and overloaded transformers.       Several
     companies market the product, which is readily available
     through purchase, rental or the services of a thermographer.
Deaner, 1992 WL 209966, at *2.
     7
      We would reach the same conclusion even if we could apply a
more exacting standard of review. Applying the four factors from
United States v. Dunn, 480 U.S. 294, 300-03 (1987), the steel
building clearly is beyond the Ishmaels' residential curtilage.
The building, for example, stood 200 to 300 yards from the
Ishmaels' mobile home and was not enclosed within a fence that also
surrounded the home. See Ishmael, 843 F. Supp. at 209-10.

                                  15
intrude up to the very windows of the building on the basis of the

`open fields' doctrine simply because it was outside the curtilage

of a home, would eviscerate the Fourth Amendment."       Id.   The

Supreme Court, in fact, has held precisely the opposite. In United

States v. Pace, 955 F.2d 270 (5th Cir. 1992), law enforcement

officers came abreast of the defendant's barn, which stood beyond

the residential curtilage, and peered inside the barn to observe

the defendant's drug operation. The defendant argued that the barn

qualified as a business and that the barn's surrounding area was

protected under a theory analogous to the home curtilage theory.

Noting that the Supreme Court effectively rejected this theory in

United States v. Dunn, 480 U.S. 294, 303-05 (1987), we concluded

that "there is no business curtilage surrounding a barn lying

within an open field."    Pace, 955 F.2d at 276.8     The officers

therefore were entitled to "come as close to the structure as

necessary to look inside without physically entering."   Id.

     Similarly, the officers in this case were entitled to observe

the steel building either by air or on foot because the building,

     8
      In Dunn, which involved facts nearly identical to those in
Pace, the Supreme Court accepted for the sake of argument that the
defendant's barn was a business. Dunn, 480 U.S. at 303. The Court
then stated:
     the officers never entered the barn, nor did they enter any
     other structure on respondent's premises.       Once at their
     vantage point, they merely stood, outside the curtilage of the
     house and in the open fields upon which the barn was
     constructed, and peered into the barn's open front.       And,
     standing as they were in the open fields, the Constitution did
     not forbid them to observe the phenylacetone laboratory
     located in respondent's barn. This conclusion flows naturally
     from our previous decisions.
Id. at 304.

                                16
like the barn in Pace, stood in an open field.                   And, as we have

already discussed, the fact that the officers enhanced their

observations with a thermal imager does not require a different

conclusion.       The device, when used in an "open field," does not

offend     the   Fourth   Amendment     because    it    is   passive   and   non-

intrusive.       The sanctity of one's home or business is undisturbed.

We therefore conclude that the DEA's warrantless use of a thermal

imager in this case was not an unconstitutional search.

                                       III.

      Having concluded that the warrantless use of a thermal imager

was not unconstitutional in this case, we now turn to the question

of whether the device's readings, in conjunction with the remainder

of   the    evidence    the    DEA   proferred    to    the   magistrate     judge,

established the necessary probable cause to issue the warrant.                   In

determining whether probable cause exists, "a magistrate judge must

make a practical, common-sense decision as to whether, given all

the circumstances set forth in the affidavit, there is a fair

probability that contraband or evidence of a crime will be found in

a particular place."           United States v. Byrd, 31 F.3d 1329, 1340

(5th Cir. 1994).          Reviewing courts (including district courts)

should afford a magistrate judge's decision "great deference."

Illinois v. Gates, 462 U.S. 213, 236 (1983); United States v.

McCarty, 36 F.3d 1349, 1356 (5th Cir. 1994); United States v.

Robertson, 39 F.3d 891, 892 (8th Cir. 1994).

      The    totality     of   the   circumstances      in    this   case   clearly

indicates a fair probability that the Ishmaels were cultivating

                                        17
marijuana in the steel building's substructure.                       Rohn Ishmael, for

example, was extremely careful not to reveal the need for the

concrete re-mix. The substructure had been elaborately constructed

with its own electricity supply and was being fed water from the

nearby      pond.         The     substructure's     exhaust      fan      operated    on   a

continuous          basis.        In    addition,    the    Ishmaels       phone   records

indicated          that    their       phone   had   been    used     to    call   various

horticulture shops, two of which appeared on a law enforcement

computer        data      base.        The   Ishmaels'     electric     utility    records

demonstrated that the substructure was consuming an inordinate

amount of power, particularly when compared to the mobile home's

power      usage.         Finally,       and   perhaps     most   importantly,        expert

thermographers analyzed the two readings from the thermal imager

and concluded that the inordinate amount of heat emanating from the

substructure was consistent with indoor cultivation of marijuana.

Construing this evidence in a "common-sense manner,"9 we conclude

that probable cause existed for the issuance of the warrant.                             See

Robertson, 39 F.3d at 893-94 (readings from a thermal imager, when

combined           with    informant's         tip   and     police        officer's     own

observations, establish probable cause).

                                               IV.

               9
          "Like the district court, . . . we construe the
[government's] affidavit in a common-sense manner." McCarty, 36
F.3d at 1356.
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        For the reasons stated above, the district court's order

granting the Ishmaels' motion to suppress is REVERSED and the case

is REMANDED to the district court for further proceedings.

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