In this appeal, we decide for the first time in this circuit whether surveillance of a mobile home using a thermal imager constitutes a search under the Fourth Amendment. Because appellant exhibited neither a subjective nor an objective expectation of privacy in heat vented from his mobile home, we find that the thermal imagery did not constitute an impermissible search. We AFFIRM.
I. FACTUAL AND PROCEDURAL BACKGROUND
In May, 1991, agents of the Florida Department of Law Enforcement (FDLE) used a thermal imager to scan a mobile home in Venus, Florida. Appellant Jerry Lee Ford owned the mobile home, which was located on land leased by Ford and his codefendant, Dorothy Ford Longmire. Acting upon information that Ford and Longmire were growing marijuana inside the mobile home, FDLE agents and other law enforcement officers covertly approached the structure late at night. The officers entered over a locked gate and traveled a quarter of a mile onto the leased property. They established surveillance in thick foliage approximately thirty-five to forty-five yards from the mobile home.
An FDLE agent viewed the mobile home through a thermal imager, a passive, non-intrusive device that measures heat in the infrared range. A thermal imager detects minute differences in temperature on the surface of objects and displays that information visually. The agent determined that the mobile home was emitting an inordinate amount of heat through its floor and walls; this finding was consistent with other indoor growing operations, which generate excess heat because of their use of artificial lights. Based upon information gained from the thermal imager and from other sources, the FDLE obtained a search warrant for the mobile home.
When the FDLE executed the search warrant, they discovered a sophisticated hydroponic laboratory and over four hundred marijuana plants. To prevent outsiders from observing this operation, Ford had boarded the mobile home’s windows behind curtains. Ford had also punched holes in the floor of the mobile home and installed a blower to vent the excess heat generated by the artificial lights. Both Ford and Longmire were arrested and charged in a two-count indictment for conspiracy to possess marijuana with intent to distribute, in violation of 21 U.S.C. § 846, and for possession of marijuana with intent to distribute, in violation of 21 U.S.C. § 841(a)(1).
Prior to trial, Ford moved to suppress evidence seized from the mobile home. He argued that the FDLE lacked probable cause to support the search warrant. Additionally, he challenged the FDLE’s warrantless use of a thermal imager, arguing that such a scan constituted an impermissible search under the Fourth Amendment.
The suppression motion was referred to a magistrate judge, who recommended that the district court deny the motion because Ford had failed to establish standing to object to the search. Alternatively, the magistrate judge rejected the merits of Ford’s suppression motion, finding that the search warrant was supported by probable cause. Further, the magistrate judge concluded that thermal imagery did not constitute a search violative of the Fourth Amendment because Ford did not have a reasonable expectation of privacy in heat escaping from his mobile home. The district court adopted the magistrate’s report and recommendation and denied Ford’s suppression motion.
After the jury had been sworn, Ford renewed his motion to suppress. 1 In addition *994 to challenging the FDLE’s warrantless use of a thermal imager, Ford argued that the affidavit supporting the search warrant relied upon stale information. Ford also claimed that the FDLE’s act of trespass onto Ford’s leasehold itself constituted a warrant-less search. Ford explained that he had not introduced these two grounds earlier because they were based on discovery materials that the defense had received the previous night. The district court denied the renewed motion to suppress without comment. Ford was convicted for possession of marijuana with intent to distribute.
II. DISCUSSION
Ford challenges the district court’s denial of his suppression motions on three grounds. He contends (1) that the FDLE agents conducted a warrantless search by invading the curtilage of his mobile home, (2) that the use of the thermal imager was a warrantless search, and (3) that the area around his mobile home was part of his commercial curtilage, should the court find that the structure was not a residence. Because Ford did not raise his curtilage claims in his pretrial suppression motion, only the issue of whether the thermal imagery constituted a warrantless search was preserved for appeal. 2
Whether the district court erred in denying Ford’s suppression motion is a mixed question of law and fact. We review the district court’s factual findings for clear error, and we review
de novo
the district court’s application of law to those facts.
United States v. McKinnon,
A. Standing to Object
Whether Ford has standing to object to the search is the threshold issue in this case. The government contends, and the district court held, that Ford failed to establish his standing in an affidavit or a signed statement of facts supporting his motion to suppress as required by Local Rule 10 H for the Southern District of Florida. Local Rule 10 H provides that “[a]ll motions in criminal cases which require evidentiary support shall be accompanied by a memorandum of law and a signed statement of the facts relied upon for the motion.” S.D.Fla. Local R. 10 H. We have held that “a motion to suppress must in every critical respect, including allegations of standing, be ‘sufficiently definite, specific, detailed, and nonconjectural to enable the court to conclude that a substantial claim is presented.’ ”
United States v. Eyster,
Although Ford did not append a separate signed statement of facts to his suppression motion, the motion itself refers to the searched premises as “Defendant’s mobile home” and as “a private home.” Rl-52. In addition, Ford’s memorandum of law supporting his suppression motion states that Ford leased the property where the mobile home was located. Rl-50. Both the motion and the supporting memorandum were signed by Ford’s attorney. Because Ford submitted signed documents alleging both ownership of the mobile home and a lease
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hold in the underlying property, we find that he satisfied Local Rule 10 H.
Cf. Eyster,
Moreover, the facts established at trial confirm Ford’s standing. The district court did not accord a hearing on the suppression motion because it determined that Ford had not established a
prima facie
case for suppression. Nevertheless, government witnesses testified at trial that Ford had a leasehold in the property at the time of the search. Consequently, we find that Ford had standing to object to the search.
See United States v. Garcia,
B. Thermal Imagery Search
Whether the FDLE’s use of a thermal imager constituted an unreasonable search under the Fourth Amendment is a first-impression issue in our circuit.
3
The touchstone for this decision is whether the alleged search violated the defendant’s legitimate expectations of privacy. Establishing a legitimate expectation of privacy is “a twofold requirement, first that a person have exhibited an actual (subjective) expectation of privacy and, second, that the expectation be one that society is prepared to recognizé as ‘reasonable.’ ”
Katz v. United States,
In
Katz,
the Supreme Court held, “What a person knowingly exposes to the public, even in his own home or office, is not a subject of Fourth Amendment protection. But what he seeks to preserve as private, even in an area accessible to the public, may be constitutionally protected.”
Id.
at 351,
Even if Ford did have a subjective expectation of privacy in the heat escaping his mobile home, he still must demonstrate that his is a subjective expectation that society is prepared to recognize as being reasonable. The Supreme Court has explained that “[t]he test of legitimacy is not whether the individual chooses to conceal assertedly ‘private’ activity. Rather, the correct inquiry is
*996
whether the government’s intrusion infringes upon the personal and societal values protected by the Fourth Amendment.”
Oliver v. United States,
One such value that has emerged as a significant factor in the Court’s Fourth Amendment analysis is the intimacy of detail and activity that a surveillance technique reveals in a particular ease. In
Oliver,
for example, the Court reaffirmed the “open fields” doctrine, first established in
Hester v. United States,
The Court has permitted enforcement officials from a federal agency to photograph a manufacturing facility using a floor-mounted, precision aerial mapping camera from altitudes of 12,000, 3,000, and 1,200 feet without a warrant.
See Dow Chemical Co. v. United States,
It may well be ... that surveillance of private property by using highly sophisticated surveillance equipment not generally available to the public, such as satellite technology, might be constitutionally proscribed absent a warrant. But the photographs here are not so revealing of intimate details as to raise constitutional concerns. Although they undoubtedly give EPA more detañed information than naked-eye views, they remain limited to an outline of the facility’s buddings and equipment.
Id.
at 238,
Similarly, in
Florida v. Riley,
As far as this record reveals, no intimate detaüs connected with the use of the home or curtilage were observed, and there was no undue noise, and no wind, dust, or threat of injury. In these circumstances, there was no violation of the Fourth Amendment.
Id.
at 452,
Like the aerial photography in
Dow,
the thermal imagery at issue here appears to be of such low resolution as to render it incapable of revealing the intimacy of detail and activity protected by the Fourth Amendment. A thermal imager operates by detecting differences in the surface temperature of objects; it cannot penetrate walls or windows to reveal conversations or, as used here, human activities. Although the device used by the FDLE can detect differences as small as half of a degree, as used against Ford it could only describe conditions within the mobile home in gross detail. The FDLE operator was able to detect high heat transmission from underneath the mobile home and in one corner wall of the structure, extending up
*997
four or five feet from the floor. Such information is neither sensitive nor personal, nor does it reveal the specific activities within the mobile home.
See United States v. Pinson,
Additionally, the Court’s precedents regarding waste disposal suggest that Ford’s expectation of privacy in his vented heat is not one that society is prepared to accept as objectively reasonable. In
California v. Greenwood,
Moreover, Ford exposed his waste heat to the public even if the emissions were not visible to every passerby. 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.
See Dow,
In Greenwood, the exposure was visual and the Court found that it was in no way diminished by the fact that the garbage was stored in opaque trash bags. Here, the exposure is heat-sensory and is in no way diminished by the fact that the source of the heat could only be detected by the use of the [thermal imager].
United States v. Penny-Feeney,
III. CONCLUSION
Ford challenges the district court’s denial of his suppression motion, in which he contended that the use of a thermal imager to detect heat emitted from his mobile home was an unconstitutional, warrantless search. For the reasons discussed, we find that thermal imagery, as used by the FDLE against Ford, is not an unreasonable search under the Fourth Amendment. We AFFIRM.
Notes
. Before voir dire, Ford’s attorney renewed the original suppression motion and made a standing objection to the introduction of evidence re-suiting from the search. He also renewed the amended motion at the close of the government’s case. For the purposes of our analysis, it is Ford's second attempt to renew his suppression motion which is the most significant of his three attempts.
. A party’s failure to present a suppression motion prior to trial constitutes waiver unless the district court grants relief for good cause shown, Fed.R.Crim.P. 12(f);
United States v. Richardson,
. The majority of district courts and the one other circuit that has considered this issue have held that thermal or infrared imagery is not an unreasonable search under the Fourth Amendment.
See United States v. Pinson,
