Allegheny County crime lab vying to use more advanced DNA database

Technology developed by Cybergenetics gets conclusive results from DNA mixtures

Share with others:


Print Email Read Later

The Allegheny County crime lab wants to create its own local DNA database to speed the analysis process, save money and increase the integrity of convictions.

First assistant district attorney Rebecca Spangler on Friday announced a study in the lab that will use technology developed by Cybergenetics in Oakland. The hope is that the study's results will lead to a permanent program.

The idea behind the TrueAllele technology is that the process, developed by Mark Perlin at Cybergenetics, can obtain conclusive results from DNA mixtures -- for example, skin cells of a suspect and victim mixed together -- more reliably than older DNA technology.

The national Combined DNA Index System database limits itself to only the simplest mixture profiles to be uploaded for comparison, Dr. Perlin said.

"There's a problem -- not just in Allegheny County but across the country and around the world," he said. He calls it a "national DNA mixture crisis."

He estimated that there are 100,000 cases over the past four years across the United States in which DNA has been collected, analyzed and paid for but which goes unused because of the problems with mixtures.

But with TrueAllele, Dr. Perlin said, "it's specific. It doesn't find false hits."

In addition, his software also produces results that exclude people as DNA matches, Dr. Perlin said.

That means, according to Ms. Spangler, "the innocent will be excluded more quickly," and detectives can move forward with their investigations.

"We all see it as a win-win-win proposition," Ms. Spangler said. "We'll be getting better evidence. That's our goal -- to make sure we're prosecuting the right people."

It also means saving money -- both by processing information more quickly and by no longer having to hire Dr. Perlin's lab in cases involving mixtures.

Before, in a case involving a DNA mixture, Cybergenetics would be contracted to do the analysis, and Dr. Perlin would be paid as an expert to go to court to testify.

Under the new study, Allegheny County crime lab analysts will be able to serve both functions.

"The idea is to free up resources," said Karl Williams, the county medical examiner. "You never have enough people in any crime lab in the country."

The TrueAllele technology is already in place at the county crime lab and was paid for by a federal grant. What remains is training the staff to use it.

"A small lab of four or five people can handle a large county of a million people because computers do all the work," Dr. Perlin said of his system.

Dr. Williams said the current backlog in the crime lab has nothing to do with matching profiles. The bottleneck comes in the beginning of the process, he said.

"It's looking at the evidence [gathered by investigators] to find whether there's probative material -- DNA -- there," Dr. Williams said. The rest of the process, he said, is automated.

Ms. Spangler has been talking to the FBI about the new study, and she said she expects the agency to sign off on the project next week.

The local database will serve as a supplement to what already exists from the state police and FBI, she said.


Paula Reed Ward: pward@post-gazette.com, 412-263-2620 or on Twitter @PaulaReedWard.

Join the conversation:

Commenting policy | How to report abuse
To report inappropriate comments, abuse and/or repeat offenders, please send an email to socialmedia@post-gazette.com and include a link to the article and a copy of the comment. Your report will be reviewed in a timely manner. Thank you.
Commenting policy | How to report abuse

Advertisement
Advertisement
Advertisement

You have 2 remaining free articles this month

Try unlimited digital access

If you are an existing subscriber,
link your account for free access. Start here

You’ve reached the limit of free articles this month.

To continue unlimited reading

If you are an existing subscriber,
link your account for free access. Start here