From One Step Ahead
Baton Rouge was gripped by fear. A monster was on the loose, raping and murdering women who lived in this Louisiana city and its surrounding communities. Between September 2001 and March 2003, the killer claimed at least seven victims. Terrified women stayed home at night; some even talked about dying their hair blond, since the so-called Louisiana Slasher seemed to prey on brunettes.Police knew they were looking for one man, because they had matched DNA samples taken from the victims. And one witness had seen a victim in the company of a white man. But the search dragged on with no leads, no likely suspects. Then the Baton Rouge police caught the biggest break of their investigation -- a new DNA test that can determine a person's ancestry. Standard DNA tests can determine sex, but tell nothing about someone's appearance.
The police quickly shipped off their evidence and discovered that their killer was in fact an African American. By ruling out white suspects, investigators could narrow the search. Baton Rouge police used this cutting-edge technology, combined with some old-fashioned detective work, to arrest Derrick T. Lee. (He has entered a plea of not guilty; his trial is scheduled for this spring.)
If you happen to watch "COPS" or read the police blotter page in the local newspaper, you know that today's typical law enforcement officer totes much more than a pistol and a night stick. High technology has become so much a part of police work that it's no longer surprising to see video cameras mounted on the dashboards of patrol cars or to hear that officers used luminol spray (which makes bloodstains glow, even if they've been scrubbed clean).
But researchers continue to look for ways to keep our nation's crime fighters one step ahead of the bad guys. Here's a look at some futuristic law enforcement innovations that are making America safer.
Meet the new sketch artist. While prosecutors today routinely use DNA taken from crime scenes to help convict offenders, the analysis doesn't tell police much about whom they should be looking for in the first place; widely used tests today only reveal a person's sex. But as the Derrick Lee case shows, that's changing. Using a huge database of genetic information from people all over the world, scientists at Penn State University devised a test that looks for "markers" on DNA that give strong clues about a person's ancestry.
The test, known as DNAWitness, can determine whether a person is most likely European, African American, Asian or Native American. (People of Hispanic heritage tend to have a mix of ethnic groups.) Crime researchers in Britain are currently working on a test that they hope will help detect hair color and even facial characteristics.
Leave no trace? Good luck. Scientists at the University of Ottawa Heart Institute have a method for extracting DNA from the microscopic remnants of skin left behind when a person touches an object. The test can be performed in minutes at the crime scene. The process, which is not available yet, also works for blood, hair, saliva, or even a flake of dandruff.
Rover, roll over. Why stop with human DNA? Researchers are also perfecting ways to identify plant DNA, which would have many uses, including the ability to trace seized shipments of illegal drugs to a given distributor.
Forensic scientists are developing methods to identify animal DNA. After all, one in three homes in the United States contain a potent source of criminal evidence: a family cat or dog. As pet lovers know, fur clings to clothing. In one celebrated case, police on Prince Edward Island, Canada, linked white hairs on a bloody jacket found near the scene of a murder to their prime suspect -- who owned a cat named Snowball.
Computers With a Badge
Sharp focus on fingerprints. Police in Kirkland, Washington, were frustrated. They had a suspect in the murder of a 27-year-old Bible-studies student: her neighbor, Eric H. Hayden. They also had a bed sheet with a bloody hand print. But the pattern on the fabric caused the fingerprints and palm prints to be unclear, making it impossible to match them to Hayden's hand. Enter Erik Berg, a forensic field supervisor with the police department in nearby Tacoma. Berg took digital photos of the prints and, using a computer program, filtered out the background "noise," producing clear prints that helped convict Hayden, who is now serving 26 years in prison.Looking for fingerprints remains an essential part of any crime-scene investigation. However, criminals rarely leave behind pristine impressions. Berg's innovative technique, which is now available to police departments in the form of software called More Hits, enables police to read smudged or partial prints. "It's like using the fine tuner on your television," says David Witzke, vice president of PC Pros, the Washington State-based company that sells More Hits.
You can run ... Kansas City police were left scratching their heads when they investigated the murder of a 39-year-old woman in 2000: The killer had removed and hidden the victim's clothes and other incriminating evidence. But investigators were able to scrape tiny bits of DNA from under the woman's fingernails; apparently she had put up a fight and scratched her assailant. The genetic information was plugged into an FBI-run database known as CODIS (Combined DNA Index System). This network lets federal, state and local crime labs exchange and compare DNA electronically. The Kansas City cops hit pay dirt: The DNA matched that of a paroled rapist from Arkansas named Wayne DuMond. Last January, DuMond was sentenced to life in prison without parole.
"And after the weather, the crime forecast." Imagine understaffed police forces being able to predict the best areas to deploy their officers. Using computers, scientists at the Heinz School at Carnegie Mellon University in Pittsburgh tracked minor and major crimes for more than a decade in two cities -- Rochester, New York, and Pittsburgh, Pennsylvania.
After running extensive statistical analyses, the scientists discovered, for example, that an uptick in minor crimes such as vandalism usually precedes, by about a month, more serious property crimes such as burglary and larceny.
When the researchers road-tested their program in Rochester and Pittsburgh, they were able to predict crimes with at least 80 percent accuracy. What's more, they could narrow down where the crime would take place to an area as small as an individual police beat -- about one square mile. By the end of this year, the researchers hope to begin distributing the software to precincts across the country.
Reach out and bust someone. While criminals often seem to strike in a random fashion, statistical analysis of crime locations can disclose patterns. That's useful when police are hunting for serial criminals, says Texas State University criminologist Kim Rossmo, who created a concept called geographic profiling. "If we can decode those patterns, we can use the information to focus the investigation," says Rossmo, a former cop.
Rossmo notes that criminals tend to do their dirty deeds close to home -- but not too close. He has developed software that analyzes an area where linked crimes have occurred, then isolates a tiny section where the crook most likely lives. That allows police to focus on specific suspects. In one case, police in Midland, Ontario, used geographic profiling to nab a prolific burglar. The system nearly drew a circle around the suspect's home.
Space-Age Crime Solving
Crime lab in a box. DNA testing is touted as the cutting edge of forensic science, but the high-tech workhorse of most crime labs has long been the gas chromatographer-mass spectrometer (GC-MS). These bulky instruments identify organic compounds by vaporizing them and analyzing the resulting gas molecules. But transporting substances -- such as chemical weapons, residue from explosives and fire accelerants, and drugs -- to crime labs takes time and can be dangerous.
"You'd have a huge advantage if you could have this laboratory instrument in the field," says analytical scientist Peter Nunes, of the Forensic Science Center at Lawrence Livermore National Laboratory, which is part of the U.S. Department of Energy.
So Nunes and colleagues shrank a standard GC-MS -- which weighs between 250 and 300 pounds -- down to 75 pounds, or about the size of a small ice chest. This portable GC-MS is already on the market and is in limited use by the Los Angeles County Sheriff's Department.
Crime rates have fallen in the United States over the last decade, and there's some evidence that innovations in technology have encouraged that trend. Imagine the dampening effect that better crime detection -- not to mention prediction -- will have on future criminals. Holmes had Watson: Isn't it comforting to know that tomorrow's cops will have science by their side?