Portland PD Wants to Use DNA to Get Guns Off Street

July 11, 2013
The department's Gun Task Force hopes to use evolving DNA technology to determine who may have pulled the trigger or gripped a gun used in a shooting.

Portland police routinely collect blood or saliva samples from a crime scene to get a suspect's DNA profile.

But now, the bureau's Gun Task Force hopes to use evolving DNA technology to determine who may have pulled the trigger or gripped a gun used in a shooting.

The bureau is seeking a five-year contract of up to $350,000 with Virginia-based Bode Technology Group Inc. to help investigators identify DNA from skin cells, sweat or oil glands left behind on weapons confiscated by police.

Sgt. Cathe Kent, supervisor of the Gun Task Force, pursued the technology because she said officers are having a hard time proving who a gun belongs to, particularly when police find it under a car seat or in a glove box in traffic stops after drive-by shootings.

Officers now try to lift fingerprints from guns, but the textured surface make its difficult to get much that's useful. And Oregon's state crime lab doesn't have the resources to routinely do DNA analysis on firearms unless the evidence is linked to a homicide or rape case, said Brian Ostrom, forensic supervisor at the state lab.

"A lot of these cases we can't make for felon-in-possession-of-a-weapon charges. Those are the cases where Touch DNA will be real valuable to us," Kent said. "In our eyes, these are people who are going to potentially shoot people or have shot people. We need to get these guns off the street and out of the hands, in particular, of felons."

Touch or "trace" DNA can be recovered from microscopic amounts of cellular material from guns, victims, their clothes or other objects. As few as five to 20 skin cells are all that's needed to obtain a DNA sample, according to the Bode Technology lab.

Portland police would send DNA evidence from guns to the Virginia lab if the City Council approves the proposed contract as expected today, joining other law enforcement agencies across the country in broadening the analysis of DNA for investigative leads.

"It's more of a new application of an old technology," said Max Houck, director of the Department of Forensic Sciences in Washington, D.C., an independent lab funded by the district.

Portland gun and gang enforcement officers have been trained how to swab a gun's trigger, grip, slide or magazine for potential DNA, using two specially packaged Q-tips that the private lab provides for each swab. Officers must wear respirator masks and gloves when taking the swabs to avoid contamination.

The bureau plans to be judicious about which guns to analyze. Kent estimates she'll send five guns a month to the lab. To start, the bureau would send samples after they identify a potential suspect and want to confirm whether DNA on a recovered gun matches the suspect's DNA.

The technology has limitations.

While it now allows for DNA detection with smaller samples of biological material, forensic experts caution that it can yield just a partial profile of a single person -- or DNA profiles from more than one person who touched the gun.

DNA evidence also doesn't conclusively tell an investigator when or how someone's DNA got on the gun.

"Guns are very portable objects, so that's one of the concerns," Houck said.

If a gunman shook another person's hand and then touched a gun, for instance, it's possible that both of their DNA would be on the gun, experts say.

The technology is effective only with sufficient biological material recovered.

"Think of it as picking up cookie crumbs, and trying to decide if they're from a chocolate chip or oatmeal cookie," Houck said. "That will depend on how many crumbs there are, and how they're collected."

Police still need witness accounts or video surveillance to support the evidence.

"Does it prove the case? No. But it certainly can help you," said Scott Kerin, chief of the gang prosecution unit in the U.S. Attorney's Office in Oregon.

Portland police expect that each gun analysis will range from $175 to $350, and the cost per year will be $70,000, funded through federal asset forfeiture money. They chose Bode Technology from six companies that submitted bids, Kent said.

It's not unusual for Portland officers to pull over a car after a drive-by shooting, recognize the people inside as convicted felons or gang members and find a gun hidden away, Kent said. But then everyone denies the gun belongs to them.

Sometimes, police have arrested the girlfriend of a suspected gunman who claims the gun is hers to shield her convicted-felon boyfriend from facing a more serious crime in federal court. The girlfriend would face a misdemeanor weapons charge instead.

"It's real frustrating because we know it's not theirs," Kent said. "A lot of gangsters are getting away with it."

Copyright 2013 - The Oregonian, Portland, Ore.

McClatchy-Tribune News Service

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