Crime lab suspends ‘touch’ DNA tests
Big demand in burglary cases forces cutback
The thieves leave invisible evidence on kitchen countertops, china cabinets, garage doors and steering wheels that can lead to their undoing: microscopic skin cells that contain their DNA.
In Harris County, these “touch DNA” samples have in recent years identified hundreds of suspects in home burglaries and car break-ins that would have been nearly unsolvable without them.
But now the Harris County Institute of Forensic Sciences has sent out a memo to the 69 law enforcement agencies it serves suspending touch DNA analysis due to diminished resources and burgeoning demand.
Officials were forced to temporarily halt the service, ironically, because testing for touch DNA has been so successful.
“We didn’t anticipate this remarkable growth and what law enforcement has done to embrace DNA testing services in general,” said Dr. Roger Kahn, the forensic institute’s crime laboratory director. “We need to reassess our service levels in order to keep up.”
The suspension will not affect the Houston Police Department, which relies on the city’s crime lab to perform DNA analysis. The Houston Forensic Science Center began performing DNA analysis in some property crime cases after the city cleared HPD’s backlog of thousands of rape kits awaiting DNA testing.
But the county crime lab’s suspension of the cutting-edge forensic test-
ing, which it took the initiative to offer eight years ago, could impact property crime investigations for dozens of law enforcement agencies. Higher chance of match
Crime laboratory officials understood back then that touch DNA testing would give investigators a much higher likelihood of finding burglary and robbery suspects when DNA found on crime-scene swabs was matched with DNA samples catalogued in the FBI’s Combined DNA Index System database, or CODIS, a national database used to store DNA profiles. Criminals can wear gloves to keep from leaving fingerprints at crime scenes. But even gloves don’t necessarily protect them against leaving touch DNA samples. Here’s why: They can leave touch DNA samples on the outside of gloves with their bare hands as they put the gloves on.
In 2008, an early year for touch DNA testing, the forensic institute received 528 samples to analyze. By last year, it had received 2,789 samples, according to data from the institute.
“They see success, so law enforcement agencies are allocating their resources to approaching investigations for property crimes using DNA more and more,” Kahn said.
Tests over that sevenyear period have yielded DNA matches to suspects in nearly 800 cases. Kahn said that is a high match rate, given the fact that crime scene evidence swabs gathered by law enforcement may or may not contain touch DNA. By contrast, little uncertainty exists in gathering blood and other bodily fluids, typically left at crime scenes in the commission of violent offenses. Testing of these samples will continue without interruption.
“Knowing that we can get DNA off something as simple as a baseball hat or any other tangible item that was touched by a suspect and get a CODIS hit is a really useful tool to have,” said Deputy Thomas Gilliland, spokesman for the Harris County Sheriff’s Office.
Gilliland said it’s too early to tell how the suspension of touch DNA-testing will impact the property crime caseload, but he hopes the crime laboratory will resume touch DNA testing soon.
In the meantime, deputies will continue to investigate property crimes using other methods, such as working with local pawn shops to identity stolen items, he said. Rising demand
For several years, forensic institute officials touted their lab as one of the few in the region to offer DNA testing in property crime cases. Crime lab officials say they will continue to perform DNA analysis in property crime cases, but only if the evidence has a high probability of yielding a DNA profile, like samples of saliva or blood. They will continue to accept touch DNA samples in violent crime cases.
Requests for DNA testing in all cases, involving both violent offenses and property crimes, have steadily increased since the forensic institute began offering the service, according to data from the Harris County Institute of Forensic Sciences.
By the end of 2015, requests for DNA testing in property crime cases alone, which make up about half of the lab’s caseload each year, are projected to have more than tripled in eight years. Of those property crimes, about 60 percent of all evidence samples submitted to the lab are for touch DNA, officials said.
The growth in caseload is in danger of outpacing the number of staff available to perform testing. In order to ensure quality DNA analysis, the suspension was put in place, Kahn said.
“At some point, it does come down to how many people are there,” he said. More funding possible
Harris County Precinct 3 Commissioner Steve Radack said he has spoken with officials at the forensic institute and believes they are proceeding in a prudent manner for the time being, although he acknowledged that touch DNA testing is important in solving property crime cases.
“A lot of people who are committing property crimes do so very frequently and sometimes several times a day,” he said. “So there is a big need to apprehend them.”
Radack said he’d be willing to discuss additional funding to help with the increased caseload. But he said officials from the institute need to come to Commissioners Court, describe the success of touch DNA testing and then explain what they would need to resume testing.
“We need a plan, we need guidance as to what the problem is and what Commissioners Court can do to help alleviate the problem,” he said.
Forensic institute officials, who say they have been working with other county officials to resolve the issues, say they hope suspending touch DNA will last for six months at most.
“I understand the concern that we are pausing that kind of service,” Kahn said. “This works. Maybe not as frequently as highyield DNA, but when this is the only hope you have of solving the crime, you’d like to have that service.”