Is digital imaging doing justice?

Nov. 1, 1998
Danny Lee Kyllo made a few mistakes in his life, and he didn`t have much luck either. His bad luck was renting the middle house of a three-house complex in Florence, OR--next to the daughter of a drug kingpin. Kyllo then made his own trouble when he began growing marijuana in a spare bedroom. ° According to his defense attorney, Kenneth Lerner, a team of federal, state, and local agents had staked out the drug dealer`s daughter in the hope of catching dad`s associates. They became sus

Is digital imaging doing justice?

W. Conard Holton, Senior Editor

Danny Lee Kyllo made a few mistakes in his life, and he didn`t have much luck either. His bad luck was renting the middle house of a three-house complex in Florence, OR--next to the daughter of a drug kingpin. Kyllo then made his own trouble when he began growing marijuana in a spare bedroom. ° According to his defense attorney, Kenneth Lerner, a team of federal, state, and local agents had staked out the drug dealer`s daughter in the hope of catching dad`s associates. They became suspicious of Kyllo once his sister moved in with the daughter. So they checked to see if his electric bills were unusually high, possibly indicating a power

drain from high-intensity plant lights that speed crop growth. And they pointed a thermal-imaging camera at his walls.

The camera detected an intense infrared radiation source that, the agents suspected, resulted from the lights. Based on the electric bills and this thermal evidence, they obtained a search warrant and moved in. Sure enough, they found the marijuana operation, weapons, and drug paraphernalia.

Kyllo pleaded guilty, was sentenced to 63 months in custody, and began an appeal process to suppress the evidence supporting the search warrant. After a few twists--such as the fact that the "evidence" of excessive electricity use was shown to be false and misleading and thus thrown out of court--the case boiled down to the question of whether the use of a thermal-imaging camera is itself a search that must meet the Fourth Amendment`s rule of justification by probable cause (see cover).

On appeal to the US Court of Appeals for the Ninth Circuit (San Francisco, CA), a three-judge panel of that court concluded, in April 1998, that "the details unveiled by a thermal imager are sufficiently `intimate` to give rise to a Fourth Amendment violation." In doing so they agreed with an earlier opinion by the Tenth Circuit Court of Appeals (Denver,CO), which had been overturned on other grounds, but put themselves at odds with circuit-court rulings in the rest of the country.

"The courts are intensely split on this issue, with the western federal circuit courts very concerned about violations of privacy," says defense attorney Lerner. The case has been appealed by the federal prosecutors to the Ninth Circuit Court en banc for a ruling by the full court. Lerner expects that, no matter what the result, the losing party will appeal to the US Supreme Court. "For the US Department of Justice, this case has national significance," says Lerner. "The current decision has created great concern that law-enforcement officials won`t be able to use thermal imagers anywhere in the ninth circuit, covering seven western states, without a search warrant."

Searching in the dark

The ability to observe people or objects at night or under cover, to automatically pick suspects out of crowd, or to transform fuzzy video images of a crime into clear or telling evidence--these are a few of the advanced imaging technologies either in the field or under development. Yet the technologies have outpaced clear legal and ethical guidelines for their use. While it is unlikely that they will be banned, restrictions and clarifications for their use are evolving that could affect manufacturers and service providers of imaging technologies.

For the moment, thermal, or infrared, imaging is the technology facing the most-frequent legal scrutiny because of its widespread use, first in the military and--for the past 20 years--in law enforcement. The principal US manufacturers of thermal equipment for law enforcement are FLIR Systems Inc. (FSI; Portland, OR), Inframetrics (North Billerica, MA), Raytheon Systems Co. (Dallas, TX), and Wescam (Flamborough, Ontario, Canada). Their cameras can be mounted on helicopters, airplanes, boats, or patrol cars, or held in the hands of officers on the ground. Priced between $100,000 and $450,000 for airborne models and $10,000 or more for handhelds, imagers have reached the point that most law-enforcement agencies can afford at least one.

"There are 353 law-enforcement agencies flying about 1200 aircraft in this country," says Roy Swetman, director of law-enforcement technologies at FSI, "and about 335 of these agencies are operating [at least one] aircraft with infrared systems." He notes that according to surveys, 85% of law-enforcement agencies want an infrared system, but it`s a matter of sufficient funding. Speaking from 29 years of experience in the Texas state police, Swetman adds, "FLIR technology is the most-significant development for law enforcement since the invention of the radio."

Equipment users have the option of joining the three-year-old Law Enforcement Thermographers Association (LETA; Edmond, OK), which provides training programs across the country. Bob Darnell, special agent of the Florida Department of Law Enforcement (Daytona Beach, FL) and a LETA trainer, says that busting indoor marijuana growers--or "structural profiling," as it is known--is just one of many applications of the equipment. The list includes tracking fugitives, pursuing vehicles, finding lost children, and--increasingly--flight safety, because the IR equipment penetrates dark or low-visibility flying conditions. "The official goal of our association is to promote the legal and ethical use of thermal imaging in law enforcement," he adds.

Incoming LETA president Dan Geiser, a senior agent with the Oklahoma Bureau of Narcotics (Oklahoma City, OK) says he doesn`t think a ruling against the government in US v. Kyllo will sound the death knell for thermal imaging in structural profiling. It will just mean modifying police protocol to get the warrant first. In fact, he hopes that the case does go to the Supreme Court to resolve the issue on the basis of merit, although he acknowledges that, in this particular case, the thermal imaging was not fully in accord with LETA training standards.

Training and standards

A failure to follow appropriate procedures in these cases is the chief complaint of Carlos Ghigliotty, president of Infrared Technologies (Lowell, MD) and a frequent expert witness for the defense. "I`ve got no problem with cops, but they fabricate evidence. And [different law-enforcement agencies] gang up for these raids and share the forfeited assets." Ghigliotti says he`s testified in 100 cases and lost only one, which was then won on appeal. He says he wins because he points out to the judges and defense attorneys how thermal imagers should and shouldn`t be used.

"It all started in 1987, when thermal imagers were first pushed as tools to obtain search warrants," he says. To keep costs low, inadequate cameras were purchased, and their settings could be manipulated to make a building look "hotter" than it really was, thus justifying suspicion of high-intensity lights for marijuana.

The purpose of LETA, of course, is to train the operators so that the images they obtain are fair and accurate. So far, LETA trainer Darnell conservatively estimates that more than 500 operators have been trained and certified by the association.

Thinking about the rules

As with all advanced-imaging technologies, the issues are both what the law permits and how the ethics are understood by all members of the law-enforcement community, from cops on the street to lawyers and judges.

Because the Supreme Court has always stressed the sanctity of the home--a heritage of British common law and the repugnance of colonials for imperial intrusions--the Ninth Circuit Court of Appeals was very concerned with the degree of intrusiveness of thermal imagers. Could they detect sexual activity in the bedroom or just hot spots where heat was escaping? Testimony on the camera`s capability convinced two judges that it could too easily detect private actions through open windows or glass.

The lone dissenting judge did not see it that way and wrote, as many other courts have written, that "the thermal-imaging device . . . intruded into nothing. Rather, it measured heat emanating from and on the outside of the house." Like a suspect`s discarded trash, it could be freely examined for evidence.

This debate may be decided by the Supreme Court, but David Harris, a law professor at the University of Toledo College of Law (Toledo, OH), argues that the basic issues of legality surrounding technology in law enforcement should be conceived more broadly. In a frequently cited Temple Law Review article entitled "Superman`s x-ray vision and the Fourth Amendment: the new gun control detection technology," Harris examines the legal implications of several imaging technologies being developed for gun detection.

Harris thinks that such technologies are a good idea because they would protect police officers by allowing them to determine, at a distance, whether a suspect has a gun. However, he stresses, "It`s a question of the situation in which a technology is used, whether there is reasonable cause to `search` the person. If the Supreme Court or others say that using a technology is not a search, then improvements on that technology will be acceptable as well."

So it`s not just about regulating law enforcement as it exists, but law enforcement as it will become when future technology is capable of gathering ever more information with less intrusiveness. Harris says, "Technology should not be the driving force in the shreds of privacy left to us." The courts, he writes, should focus on who and what police may search, and under what circumstances, not simply how they search.

And, Harris notes ironically, the usefulness of gun detectors may diminish anyway as the unexpected byproduct of new laws permitting concealed weapons to be carried by most adults who can pass criminal background checks, a trend subscribed to by half the states. Now, a person carrying a concealed weapon is no longer carrying contraband, and detecting the weapon tells a police officer nothing that would permit a further search.

Lawyers opine

The questions that Harris raises are some of those under examination by the law-enforcement community. The American Bar Association (ABA) recently adopted standards on what it terms "technologically assisted physical surveillance," which will be disseminated to policy makers and law-enforcement agencies. Hopefully it will form the basis for statutes, administrative regulations, or just points of debate.

From p. S6

A standards task force of the ABA reviewed surveillance technologies in the form of video, tracking devices, telescopic and illumination devices, and detection systems. Among the premises of the task force were that there has been only limited regulation by the courts and other rulemakers and that there is little guidance on and accountability for the uses of new technology. A perfect example is the increasing use of video cameras to observe public areas. What is an acceptable legal response when a camera set up for the offical purpose of monitoring traffic inadvertently records some illegal activity?

Christopher Slobogin, who served on the task force and is a professor of law at the University of Florida`s College of Law (Gainesville, FL), says, "The task force decided that privacy is a multifactor construct, not a simple concept. Therefore, we listed the factors that courts and law-enforcement agencies should consider when using surveillance technology."

Essentially, the long list calls for law-enforcement agencies to carefully consider the nature of the place or activity to be observed and to consider the intrusiveness of the technology. It also calls for clear control and accountability when these technologies are used and recommends that written guidelines be drafted by police departments in accordance with the ABA standards.

In a more-technical sphere, the Federal Bureau of Investigation (FBI; Washington, DC) is spearheading a technical working group on imaging technology. Although the FBI declined to discuss the group, one of its members, Herbert Blitzer, says that it started meeting in December 1997 and includes organizations such as police departments, the International Association of Identifi cation, and the American Society of Crime Laboratory Directors.

Blitzer, executive director of the Institute of Forensic Imaging at Indiana University Purdue University, Indianapolis, says the primary mission of the technical working group is to give guidance to law-enforcement agencies on what they should look for when looking at technology. One preliminary finding is that digital cameras are not yet appropriate for documenting crime scenes, although they make sense in the laboratory where greater control can be exercised over elements such as lighting. This advice should change as charge-coupled-device (CCD) camera technology continues to advance.

In the next few years, he adds, imaging applications will provide tremendous new capabilities such as extracting three-dimensional information from a two-dimensional image or recognizing faces in a crowd. Still, Blitzer feels that several nontechnical issues need attention, among them the admissibility of digital evidence in court. To ensure admissibility means establishing that the technology is reliable and the results have been handled in a manner that prevents tampering.

The world`s a screen

Admissibility goes to the heart of digital imaging. Does the image tell the truth, or enough of the truth to support justice? It took many years for film photography to gain acceptance in the courts. Digital images are arriving much faster.

Recent history has brought this home most dramatically, as witness the events following the not-guilty verdicts in the 1992 police beating of Rodney King, when large sections of Los Angeles exploded in anger. In one well-publicized event, a truck driver by the name of Reginald Denny was dragged from his vehicle and badly beaten by several men. Damian Williams was arrested and charged with throwing a brick at Denny`s head, along with other acts of mayhem.

Williams appealed his conviction to the California Court of Appeal, claiming that a photograph and video of the scene taken by a reporter from a helicopter were of poor quality and could not be linked to him. In 1996, a Kelly hearing (some times known as Kelly-Frye) had proved that what was seen on the photograph and video as a blur on the attacker`s left forearm was consistent with a rose tattoo on Williams` left forearm.

A Kelly hearing is held to establish the reliability of a new scientific technique. It must show that the technique is "sufficiently established to have gained general acceptance in the particular field in which it belongs" (People v. Kelly, 1976). The science in this case was image segmentation, a mapping technique in which the boundaries and regions of a photographic image are extracted based upon their color or luminance. The image is then mapped through a mathematical formula to create a more-discernible image.

Lenny Rudin, founder of Cognitech (Pasadena, CA), pro vided the crucial testimony in this case. The technique had been used in the medical field to locate the precise boundaries of brain tumors and in various pattern-recognition applications. "This was a most-important precedent," says Rudin. "It was the first time that video-processing testimony had been used on such a scale in court."

Rudin and colleagues have developed software and imaging techniques that make it possible to enhance fuzzy images or even determine dimensions of objects and people within images. His software applies differential equations in a sophisticated program that outperforms the simple, affordable photo-enhancing software typical of forensics laboratories. Each week his small company handles dozens of cases involving video processing and analysis, and the number is growing rapidly.

"I`ve seen lots of misuse of this technology," he worries. "There are too many `experts` out there." He cites experts who claim to be able to determine if a shape made of a few pixels is a convex (protruding) birthmark in an image of a suspect`s face or who testify to the presence or absence of facial hair. "There is currently no certain way to determine these things. Yet juries being what they are [not well educated], members are quite disposed to believe in the new world of technology, so the danger is that they are not critical."

In an effort to present legitimate image-processing techniques, Rudin and Simon Bramble (New Scotland Yard; London, UK) are cochairing conference sessions, such as the one at Photonics East (Boston, Nov. 2-6, 1998) on video investigation and forensic science technologies, and helping to organize a SPIE-affiliated working group of fellow scientists to figure out proper procedures and administrative standards for the advisibility of image-processing techniques and experts in criminal cases.

Like the best of his colleagues in digital imaging, Rudin knows that its proper use--and hence acceptance by the courts and the public--is the key to ensuring that it remains a tool of justice and not a sophisticated means to infringe on an individual`s constitutional right to privacy and to a fair trial. o

Click here to enlarge image

Infrared imaging technology adapted from military use for law enforcement works by detecting slight temperature differences between various objects and people in its field of view with a maximum range of just over half a mile.

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