New technology could help authorities identify suspects without DNA

Posted at 6:34 PM, Apr 14, 2017
and last updated 2017-04-14 21:34:04-04

New technology could help Mesa police find a man who sexually assaulted a 4-year-old in January after breaking into the home in the middle of the night.

Mesa police have released a DNA phenotype snapshot — an image generated by predicting a person's physical appearance based on their DNA.

When police have a crime on their hands with very few leads on a suspect, the DNA left at a crime scene can help them find their criminal.

"DNA: it's a blueprint. It contains all the information about that person. You just read it to help them figure out who that person was," said Ellen Greytak, director of bioinformatics at Parabon NanoLabs.

They came up with technology that some police departments are now using, including Mesa police.

"What we can do is take that DNA, do a separate analysis, and then predict information about that person; their ancestry, pigmentation, shape of face. And from that, the investigators can narrow down the suspect list," Greytak said.

She said the technology doesn't provide definitive answers, but it helps police focus their investigation by the process of elimination based in science.

"[For example] we might not be able to say for sure that this person has blue eyes versus green eyes, but they're definitely not brown," Greytak said.

Parabon already has a large database of DNA from people whose appearance they already know to help in the prediction.

"We know their eye color, for example, so we've used that data to pull out the parts of the DNA that you tend to see in people in blue eyes and that are different from DNA you see in people with brown eyes, for example," Greytak said.

Testing costs police departments $3,600.

Parabon has about 100 cases going right now since they've begun working with police departments around the U.S. in late 2014.

So far one snapshot has helped in a suspect being caught and prosecuted, Greytak said.