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Infra red


New Member
I’ve got a question about heat signature….Leo was chasing someone through the neighborhood the other night. While they were circling I noticed that the spot light went off from time to time. I know they have FLIR. And I also know they are not allowed to just scan a neighborhood.
How many times does Leo “accidentally” stumble upon a grow room while searching for a suspect?
Also…are there any good sources of data on IR. If my room is 80 degrees and I keep the rest of the house at 80 degrees how could Leo see anything? Granted that hot spots such as the top of a light fixture will be covered by a heat shield used for engine compartment fire walls.
I’m kinda freaked by an accidental find of my grow room.
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New Member
Have you ever heard of any one getting popped that way Boss?


New Member
I think that you have a better chance at winning the lottery than getting popped off like that. Its almost ALWAYS because someone opens their mouth. Just be discreet and don't have "traffic" at the spot. A good grow must be controlled and that includes the home that it is being grown in as well :48:


Well-Known Member
I am not so sure that in California they cannot just fly around looking for hot spots, but I could be wrong. Tony is right though. usually it is someone opening their mouth, a neighbor that thinks something is up, then they get a warrant to fly over and bust in your door.

Darth Skunk

New Member
Yea man i wouldnt worry....1 reason to be cautious is maybe if you lived in a high crime neighborhood then maybe thats a possibible factor to random pop. In my experience 95% of the time its word of mouth. Just be smart about it stay on the DL and you should be gtg.


New Member
What about someone cooking something on the stove, there would be hot spots there right? Definitely better just keep it so yourself, don't show anyone.


Well-Known Member
Thermal imaging: much heat but little light - legal aspects of the thermal imager
FBI Law Enforcement Bulletin,The, Dec, 1997 by Thomas D. Colbridge

Criminals quickly adopt advances in technology to pursue ill-gotten gains. Law enforcement officers should just as quickly adopt new technology as weapons against those criminals. However, unlike criminals, police officers must act within the confines of their federal and state constitutions. The use of advanced technology in the "often competitive enterprise of ferreting out crime"(1) raises concerns that individual liberties will be sacrificed in the increasingly complex war on crime. Right or wrong, the specter of Orwell's "Big Brother" looms large in the public's mind whenever a new crime-fighting device is unveiled. The thermal imager, or forward looking infrared device (FLIR), is an example.
Related Results
Several court decisions illustrate the constitutional arguments for and against police use of thermal imagers without a search warrant. Within certain guidelines, law enforcement can use thermal imagers in compliance with the requirements of the Fourth Amendment of the U.S. Constitution.
All objects with a temperature above absolute zero emit infrared radiation. The hotter an object gets, the more infrared radiation it emits. These emissions cannot be seen with the naked eye. However, a thermal imager can detect infrared radiation emitted from an object and convert its readings into a two-dimensional, black-and-white picture.
The picture contains various shades of gray, depending upon how much infrared radiation the object is emitting. The hotter areas emit larger amounts of infrared radiation and are lighter in color; the cooler areas appear darker. The device does not measure the actual temperature of its target; it only detects the relative temperatures of different areas of the object. A thermal imager is extremely sensitive and reportedly can detect temperature variations as small as 0.1 degrees centigrade.(2) The images created by the device can be projected onto a small viewing screen or preserved on video- tape or photographs. The thermal imager is small enough to be hand- held, but often is mounted under a helicopter and flown over its target.
The technology is not new. The military has used it for years on the battlefield. Law enforcement has adopted the device only recently, using it in search and rescue operations, fugitive apprehensions, and along the border to detect drug smugglers and illegal border crossings. Moreover, thermal imagers have been particularly helpful, albeit controversial, in the detection of indoor marijuana-growing operations.(3)
The Fourth Amendment to the U.S. Constitution prohibits unreasonable searches and seizures by the government.(4) In the now famous case of Katz v. United States,(5) the Supreme Court redefined a search. Recognizing that the Fourth Amendment protects "people, not places,"(6) the Court said that a search occurs whenever the government intrudes into a person's reasonable expectation of privacy.
Justice Harlan, concurring in Katz, formulated a useful, two-pronged test to determine when there is a reasonable expectation of privacy: 1) Does the person have a subjective or actual expectation of privacy? and 2) Is that expectation one that society is willing to accept as reasonable?(7) If the answer to both questions is "yes," any police infringement upon that expectation is considered a search.
If the police action is a search under the Katz definition, the next question is whether the search is reasonable. The Fourth Amendment does not prohibit all searches, only unreasonable ones. The Supreme Court has made this inquiry simple. Any search made without a warrant is per se unreasonable, unless it can be justified by one of several narrowly defined exceptions to the warrant requirement.(8) The Supreme Court prefers the use of search warrants. The application for the warrant takes the issue of the existence of probable cause to search away from the investigating officer and places it before a neutral and detached magistrate, adding an additional measure of protection for the private citizen.(9)
The Supreme Court has not heard a case on whether targeting a residence with a thermal imager is a search requiring a warrant. However, the question has reached several lower federal courts and some state courts. Decisions have gone both ways. Officers using thermal imagers must understand both sides of this argument in order to avoid violating constitutional requirements.
Most of the courts have decided that targeting a building with a thermal imager is not a search under the Fourth Amendment.(10) United States v. Penny-Feeney(11) was one of the first cases to consider the matter. The court's reasoning has influenced many other courts on the issue.
The Facts
Officers in Hawaii received information from two anonymous sources that Penny-Feeney had sold marijuana in California before moving to Hawaii and continued to do so. They told police that Penny- Feeney had grown marijuana in her home for 3 years, and plants were being harvested every 6 weeks. They provided a wealth of detail about the operation. Officers obtained a search warrant for a package sent to Penny-Feeney from California. They discovered $2,700 in cash that was detected by a narcotics dog. Officers observed Penny-Feeney pick up the package and take it to her home. Police later contacted a known informant who had visited Penny-Feeney's residence and seen the marijuana- growing operation. He, too, described the operation in great detail. Many of the details provided by the informants were corroborated by the police.
Without a warrant, police flew over Penny-Feeney's residence at an altitude of between 1,200 and 1,500 feet in a helicopter fitted with FLIR. The thermal image of her house showed the walls and other areas of her garage as bright white, indicating significant heat was escaping from the garage. Adjacent but similar structures did not appear the same when scanned by the FLIR. The FLIR operator said the thermal image of her house was consistent with that of a structure being used for an indoor marijuana-growing operation.
Police got a warrant to search Penny-Feeney's residence using all of this information, including the results of the FLIR scan. During execution of the warrant, police found marijuana plants and paraphernalia used to grow marijuana indoors. Penny-Feeney and her husband were indicted. They filed a motion to suppress the evidence, alleging, among other things, that the warrantless use of the FLIR by police was an illegal search under the Fourth Amendment.
No Subjective Expectation of Privacy in "Waste Heat"
Using the Katz analysis, the district court concluded that the defendants had no subjective or actual expectation of privacy in the area scanned by the police with the FLIR. The court said that FLIR is limited to "detecting differences in temperature on the surface of the object being observed," and "did no more than gauge and reflect the amount of heat that emanated"(12) from the defendants' house. In other words, the FLIR registered only heat escaping from the defendants' house. The court described this escaping heat as waste heat, or "abandoned heat,"(13) because the defendants had not tried to prevent its escape. Indeed, they used fans to vent the heat to the outside, voluntarily exposing it to the public. They never attempted "to impede its escape or exercise dominion over it."(14)
Under these circumstances, the court concluded that the defendants did not have an actual or subjective expectation of privacy in the waste heat. Consequently, the first prong of the Katz case was not satisfied: There was no actual expectation of privacy, so there was no search under the Fourth Amendment that would require a warrant.
Expectation of Privacy Not Objectively Reasonable
The court went on to say that even if the defendants had an actual expectation of privacy in this waste heat, it is not an expectation that society is willing to accept. In other words, the defendants could not satisfy the second prong of the Katz test. The court compared heat vented to the outside to trash left for collection on a public street. The Supreme Court has said that garbage bags left for pickup generally are known to be accessible to all manner of animals and people while awaiting the trash collector. In addition, the trash is voluntarily given to trash collectors, who may handle it in any fashion they choose, including giving it to government agents. Therefore, any actual expectation that the garbage will be private is not objectively reasonable.(15) By analogy, the court reasoned that waste heat is like trash: Any expectation of privacy in waste heat is objectively unreasonable because individuals may do what they want with it once it is exposed to the public.
Sense-Enhancing Technology Not Overly Intrusive
The Penny-Feeney court did not consider the fact that waste heat can only be detected with a FLIR, and not the naked eye, to be legally significant. It relied upon several Supreme Court cases approving the warrantless use of "extrasensory, nonintrusive equipment, such as the FLIR" to investigate people and objects: United States v. Knotts(16) (a beeper placed in a container), United States v. Place(17) (use of a drug detection dog), and Smith v. Maryland(18) (use of a pen register). The court thought the analogy to the use of a drug detection dog was the strongest, citing United States v. Solis.(19) Like marijuana odor emanating from a package, Penny- Feeney expected the heat to leave the garage because she deliberately vented it to the outside. Moreover, the court concluded that the use of FLIR by police, like the use of a dog in Solis, was inoffensive because it did not embarrass the defendants or involve a search of their persons. In addition, heat and odor emanations are physical facts indicating a possible crime, not protected communications between people. Finally, the use of the helicopter to aim FLIR at Penny- Feeney's house was deemed lawful under California v. Ciraolo(20) and Florida v. Riley(21) because the police remained in navigable airspace, and the observation was physically nonintrusive because there was no "invasion of the home or curtilage."(22)
The Court's Conclusion
The Penny-Feeney court concluded that the police did "no more than aim a passive infrared device at defendant's home from an aerial vantage point for the purpose of detecting disposed waste heat on the exterior of the house. No intimate details connected with the use of the home or curtilage were observed, and there was no undue noise, no wind, dust, or threat of injury."(23) In other words, there was no search within the meaning of the Fourth Amendment.
The majority of courts that have considered the use of thermal imagers have adopted the Penny-Feeney result but have employed slightly different analytical reasoning. One court reasoned that whether a subject takes no steps to prevent heat from escaping or actively vents it outside, both actions demonstrate a "lack of concern for the heat."(24) Another court found that from the "balance of the evidence," the defendant had a subjective expectation of privacy because he concealed his growing operation in an underground structure; however, the court decided his expectation was objectively unreasonable.(25) All courts upholding the warrantless use of thermal imagers have agreed on the importance of two factors: the lack of a physical intrusion into the targeted area and the scanned image's lack of intimate detail.
The case of United States v. Cusumano(26) expresses the minority view that the warrantless use of a thermal imager by the police violates the Fourth Amendment. This case was decided by a three judge panel of the federal Tenth Circuit Court of Appeals. When the judges heard the case, the panel was vacated because they concluded that the issue of using the thermal imager did not have to be resolved in this particular case. However, the panel's opinion remains a clear statement of the minority view.
The Facts
In their affidavit for a search warrant, police in Cheyenne, Wyoming, included, among many other facts, the results of a warrantless thermal scan of the defendant's home and attached garage. The thermal image showed a large hot spot on one wall of the garage and a number of hot spots along the roof and near the front door of the house.
When police executed their warrant, they found an indoor marijuana-growing operation in the basement. The defendants were indicted and convicted of manufacturing marijuana. On appeal, they contended that the warrantless use of the thermal imager violated their Fourth Amendment rights. A panel of the Tenth U.S. Circuit Court of Appeals agreed.
Heat Reveals Private Activity in the Home
Using the Katz analysis, the court concluded that the defendants had an actual expectation of privacy. This court, however, framed its inquiry quite differently. The court based its analytical framework on the private activities within the house that generated the heat rather than merely focused on the heat escaping from the house.
The court said heat emitted outside the home and measured by the thermal imager is directly related to, and a function of, activities going on in the home. Viewed from that perspective, the court reasoned that the thermal imager actually created a "heat signature"(27) capable of revealing information about heat-generating activities going on inside the house. In other words, the imager painted a picture that police could translate into information regarding what the defendants were doing inside the building.
According to the Cusumano court, the question to ask is not whether the defendants expected the escaping heat to remain private, but whether they expected the indoor activities that the heat signature revealed to remain private. Clearly the defendants did, the court concluded, because they had hidden their operation in the basement and blocked the windows.
Obviously, the defendants did not take all possible steps to protect their operation from a thermal scan, but the court concluded that they should not have to anticipate and guard against "every investigative tool in the government's arsenal"(28) in order to claim an actual expectation of privacy. Otherwise, the court said, the public would be at the mercy of advances in government technology, drawing citizens into a lopsided game of "hide and seek played by the government and the people."(29)
Protecting the Privacy of Activities Within the Home Is Objectively Reasonable
The court then turned to Katz' second prong, whether the defendants' expectation of privacy was objectively reasonable. The court said the expectation that activities within someone's home would remain private is objectively reasonable because society still believes that activities carried on in the home, and not knowingly exposed to the public, should remain private. The defendants had met the second prong of the Katz test, as well. Consequently, the defendants had both an actual and an objectively reasonable expectation of privacy in the activities within their home. Therefore, the Court decided that this use of the thermal imager was a search, and the police should have obtained a warrant before scanning the home with a thermal imager.
Protecting the Sanctity of the Home
The Cusumano court acknowledged the government's right to use modern technology to fight crime, but it refused to permit the warrantless use of technology that reduces the security of people in their homes. In that regard, the court cited the case of United States v. Karo(30) to support its position. In Karo, the government placed a beeper inside a can of ether to track its movements. The beeper-laden can was taken into the defendant's house. Agents activated the beeper, revealing that the can was stored inside the residence. The Supreme Court condemned that particular use of the beeper as a warrantless search in violation of the Fourth Amendment. Using the beeper, the agents obtained information they could not have obtained from outside the curtilage of the house: namely, that the can of ether was inside.
The Cusumano Court reasoned that the use of the thermal imager was similarly objectionable: It revealed information about activities going on inside the house that police could not obtain from outside the curtilage of the home. This revelation of a single detail about activities inside the home was sufficient to violate the Fourth Amendment. Moreover, the court did not believe that the heat signature of the defendants' home was in plain view or knowingly exposed to the public because it is not customary for individuals seeking privacy to control their heat emissions, and privacy should not "hinge upon the insulating capacity of the walls."(31)
The Voluntary Relinquishment Rationale
The abandoned waste analogy was equally unconvincing to the Cusumano court. The relinquishment of control over heat emissions is hardly voluntary as it is with trash. The loss of heat is governed by the laws of physics and is not an area where people usually seek control to guard their privacy. In addition, while people expect that their trash may be invaded by scavengers, they hardly expect their homes to be scanned with thermal imagers.
For similar reasons, the court dismissed the analogy to a pen register. Because the telephone company is expected to record dialed numbers, users can be said to relinquish that information to the company voluntarily. For that reason, telephone users cannot be said to have either an actual or objective expectation of privacy in their dialing information. Therefore, police use of the pen register does not infringe upon any such expectation.
Distinguishing Lawful Activities from Contraband
The dog sniff analogy offered a more precise comparison. However, the court noted that the dog sniff detects only contraband that a person may not possess legally. The thermal imager, on the other hand, identifies heat from both legal and illegal activities in the home. The court also noted that dog sniffs generally take place in public areas, such as airports or border crossings, while in this case, a private home was the target.
Many law review commentators echo the Cusumano panel view that the use of a thermal imager is a search requiring a warrant.(32) Two state Supreme Courts have agreed.(33)
It is impossible to predict when, or even if, the U.S. Supreme Court will resolve this debate. In light of the disagreement over the warrantless use of thermal imagers, the following general guidelines for police officers using thermal imagers should ensure the lawful use of this technology.
Search Warrants
Law enforcement officers should consult their legal advisors to determine whether a search warrant is required to use a thermal imager in their jurisdictions. Of course, search warrants are always preferred. Given the current debate over thermal imagery, a warrant should be obtained whenever possible before using the thermal imager.
Probable Cause
None of the cases reviewed advocate that a thermal scan alone provides probable cause for a search. Heat is generated by many different activities, both legal and illegal. The results of a thermal scan provide but one of many facts the officer must combine into the mix of probable cause to obtain a search warrant and search the scanned building.
Placement of the Thermal Imager
The courts that have upheld the warrantless use of thermal imagers have stressed that officers using the device did not physically intrude upon the area scanned. Scanners were aimed at the target by officers standing outside the curtilage of the home or business or from aircraft flying within navigable airspace above the area. Thermal scanning conducted from within the curtilage of a home or from a helicopter flying below navigable airspace is plainly more intrusive. Officers should ensure that any scan is conducted from a location where they have authority to be.
The Capability of the Thermal Imager
One of the most important factors in this ongoing debate is the nature of the information the thermal imager provides. The Supreme Court has acknowledged that police may use new technology to enforce the laws(34) but has cautioned that there are limits: "An electronic device to penetrate walls or windows so as to hear and record confidential discussions...would raise very different and far more serious questions...."(35)
Does the thermal imager penetrate walls and reveal such "intimate details"(36) so as to implicate the Fourth Amendment? One federal court has noted that infrared photographs of a mobile home revealed rafters inside and that the home appeared to be split into two rooms.(37) If FLIR devices do reveal such intimate detail, either directly or through interpretation of the images, the argument against warrantless use of the device is stronger. If, on the other hand, the device merely reveals whether one structure is emitting more heat than another, the argument against warrantless use is weaker.
Officers using thermal imagers should document clearly the capabilities of their machines. A reviewing court certainly will inquire whether the particular imager can distinguish intimate details within the targeted building. Videotapes or still photographs of any thermal images should be made and retained for the court to see. Interpretation of the thermal images should be limited to the question of whether the targeted structure is emitting substantially more infrared radiation than similar structures in the area.
Technological innovation, like thermal imaging, continually will test the meaning and limits of the Fourth Amendment of the U.S. Constitution. The U.S. Supreme Court will no doubt have to shed additional light on the issue before the debate over the use of thermal imaging will cool.
1 Johnson v. United States, 333 U.S. 10, at 14 (1948).
2 Michael L. Huskins, Marijuana Hot Spots: Infrared Imaging and the Fourth Amendment, 63 U. Chi. L. Rev. 655, at 660 (Spring 1996).
3 Growing marijuana indoors requires the use of powerful artificial lights to simulate sunlight. These powerful lights generate a great deal of heat. That heat must be expelled to avoid killing the plants.
4 U.S. Const. Amend IV reads: "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."
5 389 U.S. 347 (1967).
6 Id. at 351.
7 Id. at 361 (J. Harlan, concurring).
8 Id. at 357.
9 333 U.S. 10, at 14.
10 See e.g., United States v. Pinson, 24 F.3d 1056 (8th Cir. 1994); United States v. Ford, 34 F.3d 992 (11th Cir. 1994); United States v. Robinson, 39 F.3d 891 (8th Cir. 1994); United States v. Myers, 46 F.3d 668 (7th Cir. 1995); United States v. Ishmael, 48 F.3d 850 (5th Cir. 1995); United States v. Robinson, 62 F.3d 1325 (11th Cir. 1995).


Well-Known Member
Technically, using IR technology to monitor the heat sources from a house without the owners knowledge or consent has been deemed as "illegal search and seizure." Boss's article was very interesting in the fact that the courts actually ruled that because the heat was vented purposely there was no reasonable expectation of privacy, and therefore the IR readings and reason for a search warrant can become admissable. This, argueably, draws a direct correlation to hypothetically growing cannabis plants right in your front yard in plain sight. Again, no expectation of privacy.

However, this is the million dollar question. If one were to use insulating products that would block any potential IR signature, would this qualify under the law as simply "securing your affects from illegal searchs" which is protected under the Fourth Amendment, or could this be construed as "tampering with evidence" due to the fact that you attempted to hide the heat signature that was linked to an illegal activity? If the heat signature is classified as evidence and proposed in order to obtain a search warrent then it stands to reason that concealing this aspect would qualify as evidence tampering in the eyes of the law, a felony in it's own right. Confusing isn't it?

When in doubt, hire a lawyer that is ready, willing and able to make the prosecuting parties job as difficult as possible using a nightmarish array of legal motions and pre-established legal precedence. The supreme court has in fact found that IR monitoring is a violation of the Fourth Amendment, but there is no doubt in my mind that the lower courts will interpret this ruling in any way other than it's face value in order to effectively circumvent it and sucessfully prosecute an individual, as is just the case described in Boss's post.

In conclusion, the law will contradict itself in any way it finds favorable to it's own devices. The ends always justify the means sort of speak. No one has ever said laws must make sense or are not open to many varying interpretations. They turn the heat up on our rights everyday, which we require like life-giving water. Sadly if trends continue, all too soon the last of or most vital and basic rights as Americans will be boiled away leaving nothing but any empty angry glowing-red kettle and memories of freedoms lost, like steam vapors to the wind. If this seems overly critical, all I can say is "truth hurts".

Fly by night and give no quarter. Stay safe. :peace:


Well-Known Member
Yes Roormn, it says since he made no effort to filter out the heat, it was legal.

So all you have to do is show a photo of a carbon filter, and it's an illegal search.

What was really interesting was them saying they saw heat escaping the house, but no mention of what they saw on the flir inside the house. Without a videotaped flir image, they would win in court, just by lieing about what they saw on the FLIR.

I think it was the witnesses , once again, that sunk this guy though.


On Vacation
You're more likely to get busted on things like your energy bill being higher than average, or nosey neighbors or word of mouth.


Very interesting post but leaves me with the question still do the IR blocking products work and is there other "Home Depot" options just as successful.


Found this stuff that seems to bw a great value and better than mylar because it is easier to clean. Cheaper than the home depot alternative; It is called TEKFOIL.
link-> TekFoil Reflective/Bubble/Reflective (R/B/R)
Keep the heat where it belongs with TekFoil™ Reflective Insulation. TekFoil Reflective/Bubble/Reflective (R/B/R) Insulation is designed for installation between or over framing members, on walls, floors and ceilings. Packaged in easy to handle rolls, TekFoil Insulation R/B/R can be used in conjunction with mass insulation or without. Applications extend to commercial, agricultural, residential and industrial construction.
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