Sneak thieves and cat burglars once covered their tracks by donning a pair of gloves — but no more. Their DNA can act as the smoking gun that leads to their capture, as one unsuspecting bank robber recently found out the hard way.
Police in Medford, Oregon, followed a suspect's mucous trail to make an arrest one year after he robbed the city's Rogue Federal Credit Union. After a teller mentioned the perpetrator sounded like he suffered from a head cold, investigators collected a used tissue at the scene they believed the suspect had left behind. Forensic analysts later developed a DNA profile from the tissue that matched a record in the state's DNA database.
Once relegated to major crime scenes, where investigators gathered biological evidence from blood, semen and hairs, authorities are now unearthing the utility of applying CSI-style, DNA analysis techniques to high-volume serial crimes, such as burglaries, robberies and acts of vandalism.
"Fingerprints, shoe prints and tool marks have long been the bread and butter of burglary crimes — that's what everyone looks for," says Dean Gialamas, the director of Forensic Science Services for the Orange County (California) Sheriff's Department, which processes approximately 35,000 cases per year. "We're now extending investigations one more notch to include DNA, saying this is another piece of forensic science that could answer a lot of questions in lesser crimes."
Orange County's efforts have paid off. The department, which began collecting DNA in select robbery, auto theft, burglary, larceny, gun possession and drug possession cases more than 4 1/2 years ago, has processed approximately 400 burglary cases. In this internal evaluation, the agency received 60 cold hits in the database from those samples. "That's pretty phenomenal percentage-wise," says Gialamas, who serves on the NIJ's working group on DNA forensics. "We quickly saw the value of pursuing this more aggressively."
DNA does pay
In 2003, the Miami-Dade Police Department received two NIJ grants allowing it to outsource DNA profiling for high-volume serial crimes. While Miami-Dade officials expected some profiles to match those in Florida's DNA database as a part of this effort, Bud Stuver, laboratory manager of the forensic biology section of the Miami-Dade Crime Lab, says he and his colleagues never anticipated that of the 2,700 samples processed the match rate would be as high as 52 percent.
"When I look at it in hindsight, it makes perfect sense," he says. "The individuals who perpetrate burglaries, break-ins and steal automobiles are very recidivistic people. Many of them have a history of drug use or some other type of habit. Committing these crimes allows them to support the lifestyle they have."
Stuver clarifies the matches they obtained didn't necessarily "solve" a crime, however. The agency had two types of hits coming in. In the first category, the sample matched the DNA profile of a specific individual, whereas in the second, the submitted profile matched DNA found at another crime scene. "In this case, we've identified the same perpetrator likely committed various burglaries," he says. "So you have the potential for a serial offender."
Through Orange County's DNA collection efforts, whether for a major or minor crime, Gialamas says they've found that whenever there is a hit, there's nearly always a high-volume lower felony crime on the individual's record. "The criminal propensity for accelerating and graduating to more serious crimes is the reason why I think if we take DNA at a much earlier standpoint and increase the size of the DNA database with convicted felons and crime scene samples, the odds of making a connection will rise substantially," he says.
That's not surprising either, says Stuver, who uses the word "opportunistic" to describe individuals who commit lesser crimes. These offenders take advantage of whatever situation arises, explains the 38-year veteran of forensic science. If their intent is burglary and they enter a home and find a female alone, it may become a sexual assault. If they encounter resistance from victims, the situation may escalate to homicide.