Bytes Help Take the Bite out of Crime
Stephen Jacobson observes a magnified image of the lab on a chip (center of photo) on a video monitor linked to an optical microscope. DNA fingerprinting of blood at crime scenes is one potential use of the lab-on-a-chip technology developed at ORNL.
ORNL is developing computer-driven technologies that will enable authorities to acquire or improve the quality of information needed to identify a crime suspect.
Awoman lies dead, with her blood on a patio. A detective arriving on the scene sees a knife with blood on its handle and a trail of bloody footprints along an asphalt path.
He takes out a “lab on a chip” to do a rapid blood analysis. First, he collects blood from the victim; then he uses another chip for blood on the knife and a third for the footprint blood. He carefully labels each chip. He places one chip inside a black box containing a small laser, light detector, and electronics. He checks the screen of a laptop computer.
In five minutes, he is shown the distinctive molecular characteristics, or DNA fingerprint, of one blood sample. He then processes the other blood samples and returns to the crime lab with some potentially good evidence. At the lab, he tells his colleagues, “This method certainly beats shipping off the blood samples to a conventional lab and waiting weeks for results.”
That’s the forensic fantasy. However, technology being developed at ORNL may soon turn this fantasy into a reality by making it possible to obtain DNA fingerprints quickly from blood at a crime scene for later comparison with the DNA fingerprints of blood from suspects. Mike Ramsey and his group in ORNL’s Chemical and Analytical Sciences Division (CASD) have received funding from the National Institute of Justice to develop the lab on a chip for rapid, onsite forensic analysis.
“One person could collect blood samples at the scene of the crime and do a fast analysis then, reducing the chance of contamination by other people’s blood and eliminating the chain-of-custody problem,” Ramsey says. “The chips could be made disposable to prevent cross-contamination among samples.
“We have done tests that proved that a DNA segment could be mixed with a restriction enzyme to determine the sequence of the segment’s chemical bases,” Ramsey adds. “We showed that we could obtain this characteristic DNA fingerprint in five minutes.” The lab on a chip could also be used to identify drugs of abuse, poisons, and explosives at crime scenes.
These two different bodies have been dead the same length of time—30 days. The challenge is to find chemical markers for bodies that have decomposed differently and yet pinpoint the exact time of death.
After the Murder: Narrowing Down the Time of DeathWhen police detectives find a murder victim, they take the body to the medical examiner, who will seek to determine the cause and time of death. Time of death is particularly difficult to pinpoint, but it is important to know to help determine the victim’s identity (if unknown) and to relate the crime to a possible suspect.
ORNL researchers are seeking a solution to this problem. Stacy Barshick, an analytical chemist in CASD, and her colleagues have been developing methods for identifying chemical signatures in a body that may be used to mark precisely the time interval since death. “We will be investigating the chemical changes that occur in decomposing tissues from the brain, heart, lung, kidney, liver, and muscle hours to days after death,” she says. This research is made possible through a collaboration with the University of Tennessee’s Anthropological Research Facility, which provides cadaver samples.
ORNL researchers will investigate the changes in the chemical composition (DNA, proteins, lipids, and their degradation products) of the different tissues as they decay. “We hope to determine which changes may be related to the time interval since death and in which tissues these changes show up the best,” she says. “By measuring the changes that occur at different times in different tissue, we hope to find markers that will help forensic scientists establish the time of death.”
The research is being supported by DOE’s Office of Nonproliferation and National Security. The researchers will use techniques such as gel electrophoresis, liquid chromatography, gas chromatography/mass spectrometry, and electronic aroma detection for this study. The ORNL group hopes to come up with a body of knowledge in time to help solve major crimes.
Video Imaging Tool for Aiding Law Enforcement
VITALE improves the resolution of video images. Here it allows a police detective to read the word “Kansas” on a T shirt.
In July 1995 in Chattanooga, Tennessee, a clerk in a convenience store was shot and killed during a robbery. The images on the videotape from the store surveillance camera were frustratingly fuzzy. So the police detectives investigating the crime sent the grainy footage to ORNL.
Using an early version of a software tool that forms a sharper image by extracting and compiling information from multiple images of the same subject, a group in ORNL’s Instrumentation and Controls (I&C) Division were able to show the police a clearer picture of subtle differences in the crime scene. As a result, the detectives could see the suspect’s foot and a muzzle flash from the suspect’s weapon, showing that he had fired the gun in the store. Identification of the muzzle flash discredited the suspect’s story to the police that the weapon had gone off accidentally in a back room scuffle with the clerk. The new evidence led to a guilty plea, a conviction, and a sentence of life in prison without parole. In this case, the ORNL technology also helped avoid a death penalty trial that would have cost Tennessee taxpayers $100,000 with no guarantee of a conviction.
ORNL’s Video Imaging Tool for Aiding Law Enforcement (VITALE) does more than detect subtle changes in surveillance data. It doubles the quality of the videotapes, which are often fuzzy because they are recycled perhaps hundreds of times. Using digitized frames of analog videotape, VITALE algorithms and other techniques sample multiple views of the same subject and “fuse” the video frames together to generate a higher-resolution image. Ken Tobin, leader of the I&C Division’s Image Science and Machine Vision Group, who developed the technology with group members Tom Karnowski and Tim Gee, says the technique makes it possible “to get more pixels out of the data so that facial features are sharper and license plates are more legible.” The multi-frame fusion technique, whose development is being funded by the Department of Energy, has enabled the researchers to make out words and spots on T-shirts and details of facial features and other identifying marks.
The ORNL software package will be tested by the U.S. Secret Service in mid-1999 and released commercially to local and federal crime fighters by 2000. Besides law enforcement applications, it also could be used to improve the resolution of medical and satellite images.
It had been tried many times before. Hundreds of prisoners had used this trick to escape through the prison sally port without being seen by the guards. They had hidden in a laundry truck before it left the prison. So, when Cecil tried to sneak out of the penitentiary this way, he was surprised when the truck was stopped at the sally port. A guard entered the truck and handcuffed him. “How did you find me?” Cecil asked. “It was the heartbeat detector,” the guard said.
Tim Hickerson and Vivian Baylor operate the heartbeat detector in an attempt to detect the presence of a human hidden in the truck.
A scenario like this may actually have taken place in a prison in Nashville, Tennessee, which uses the heartbeat detector technology developed in Oak Ridge. Originally called the enclosed space detection system, the heartbeat detector was the project of a team of engineers at the Oak Ridge Y-12 Plant, a nuclear facility that stores large quantities of highly enriched uranium. In 1994, they began developing the heartbeat detector as part of DOE’s “Portal of the Future” project, whose goal is to create a system that uses sophisticated devices and methods to rapidly inspect trucks passing through vehicle portals at key facilities. The original purpose of the heartbeat detector was to prevent an intruder hidden in a truck from sneaking through the Portal of the Future, say, to steal weapons-grade nuclear material or to hold people hostage.
Wavelet transform of a heartbeat signature in the noise signatures coming from a truck as detected by a geophone. The heartbeat detector can find a person hidden in a vehicle, such as this woman concealed in a truck.
When the heartbeat detector was being developed at the Y-12 Plant, Steve Kercel and Bill Dress, both of the I&C Division, were asked to solve a problem mathematically to ensure that the device would accurately detect human heartbeats amid various background signals. They developed the “fast continuous wavelet transform algorithm” for a ruggedized portable computer linked to sensors. The heartbeat signal is captured at the vehicle’s exterior by a geophone, a device commonly used to detect small disturbances in the earth. The sensor signal, which includes truck vibrations from air currents and natural resonances, is fed into the wavelet algorithm. If a heartbeat is in the signal, it will be matched and detected by the heartbeat wavelet programmed into the algorithm.
The wavelet-based heartbeat detector has become recognized as a major advance in security technology. It was independently tested at the Thunder Mountain Evaluation Center at Fort Huachuca, Arizona, where it was shown to be more than 99% reliable in detecting occupants hidden in vehicles. In 1996, the Oak Ridge technology was licensed to a private company for development into a commercial product for government and corporate security operations. In 1997, the heartbeat detector received R&D Magazine’s R&D 100 Award, as one of the 100 most significant technological product developments of the year. The detector, which was tested extensively by security personnel at the Y-12 Plant, is being implemented there.
Besides detecting prisoners and terrorists, the heartbeat detector could be used to spot illegal immigrants hidden in cars and trucks, according to Kercel. “Many people have smuggled passengers concealed in vehicles across highway borders,” he says. “One common ploy is to remove the material from inside the front or back seat and stuff the passenger into the available space. Less obvious strategies are nothing short of astounding. For example, U.S. agents recently discovered two illegal aliens wrapped around the engine of a Yugo.”
The heartbeat detector may well someday be at the heart of new technologies designed to keep prisoners in and terrorists and illegal immigrants out.
Elemental “Fingerprints” of Glass at the Crime SceneA police officer stops a driver whose car resembles one involved in a hit-and-run accident nearby. Because broken glass was found at the accident scene, the officer checks the headlights of the suspect’s car. He finds a broken headlamp. The driver says he has no knowledge of the accident. Nevertheless, the police officer gathers pertinent information from the driver. And he collects pieces of glass from the smashed headlight for analysis in the crime lab.
In the past, police detectives have compared the refractive indexes of glass from broken headlights and glass particles found on suspects’ clothing with those of glass pieces found at a crime scene. The degree to which the glass pieces linked to the suspect seemed to match those at the scene was offered as evidence in court.
Unfortunately, this technique is less effective with newer glasses because of improvements in manufacturing. A more discriminating technique is elemental analysis, because many samples of glass differ in the concentrations of trace elements present.
With collaborators from the Federal Bureau of Investigation (FBI) and the International Forensic Research Institute at Florida International University, ORNL’s Doug Duckworth (CASD), Shelby Morton (CASD), and Chuck Bayne (Computer Science and Mathematics Division) are analyzing samples of many different glasses to determine their distinctive elemental “fingerprints.” Using inductively coupled plasma mass spectrometry and statistical analysis, they are measuring the concentrations of 46 different trace elements found in glass, such as barium, rubidium, strontium, and zirconium. They are also determining the elements that will be the most useful in fingerprint comparisons—those which vary considerably in concentration from glass to glass and can be measured with little error.
“We are developing a database for the National Institute of Justice that contains the elemental fingerprint of many samples so that the likelihood of a ‘match’ can be stated,” Duckworth says. “Our goal is to produce a compact disc that would, for example, indicate the probability that glasses from different car headlights would have the same elemental fingerprint, such as identical concentrations of strontium and zirconium. Our studies should allow forensic scientists to assign a value, such as one in a million, to an association of a questioned glass to glass from a crime scene, based upon its trace element fingerprint. These studies should greatly increase the significance of glass as evidential material.”
Improving Electronic FingerprintsThe FBI has 32 million electronic fingerprints in its central database in West Virginia, and thousands of prints are electronically mailed there daily for processing. When the FBI’s Integrated Automated Fingerprint Identification System (IAFIS) goes online July 30, 1999, police officers should be able to take a digital print from a suspect with an electronic scanner, e-mail it to the FBI, and receive an identification and other information two hours later.
In support of the FBI, the Data Systems Research and Development (DSRD) group of Lockheed Martin Energy Systems has been developing the Electronic Fingerprint Image Print Server (EFIPS). ORNL’s I&C Division has been supporting the DSRD work on EFIPS. Currently, each person’s electronic fingerprint is printed on a standard FBI ten-print paper card for final processing. Until recently, printouts of 10 to 15% of the electronic fingerprints were of low quality because of darkened or smudged backgrounds. These cards were rejected and police departments were notified to obtain new electronic prints.
To solve this problem, Jim Goddard of the I&C Division developed image processing software that lets FBI operators of quality control workstations clean up the electronic fingerprint’s background. Because this software lets operators digitally improve the contrast of many fingerprints that would otherwise be rejected, most of them show up clearly when printed out. Now, only 1 to 2% of the printed electronic fingerprints are rejected by the FBI.
ORNL’s contributions are expected to improve the quality of the FBI’s tide of prints.
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