Montgomery County Officials Use DNA Samples to Create Picture of Rape Suspect

Phenotyping uses DNA gathered from biological evidence - such as skin and blood - to predict a person’s ancestry and appearance.

It’s the stuff of science fiction, but Pennsylvania officials are hoping DNA testing will lead them to the man suspected of raping a 19-year-old jogger in broad daylight.

The attack happened shortly before 11 a.m. on Aug. 1 in Montgomery County’s Norristown Farm Park. A man wearing a hooded sweatshirt despite the balmy summer weather jumped a young woman at gunpoint. Nearly six months later, Montgomery County officials have not found the suspect.

“This [crime] is really rare,” Kate Delano, a spokeswoman for Montgomery County District Attorney’s Office, said. “It’s been more than a decade since something like this happened.”

The case continued to nag local officials until they teamed up with Parabon NanoLabs, a Virginia-based company that uses the forensic technique called phenotyping to recreate faces.

On Tuesday, Montco District Attorney Kevin Steele released an illustration of the suspected rapist created with this new technology. The result is a man in his 20s or early 30s with light to medium brown skin and between 5-foot-5 and 5-foot-10 inches tall with an average build.

“Since we have our attacker’s DNA, we know who he is — we just don’t know his name and where he lives,” Steele said. “While the composite is not expected to be a photo ID of the suspect, phenotyping puts a face on the rape suspect’s DNA in the hopes that someone might recognize him and contact detectives.”

Phenotyping uses DNA gathered from biological evidence - such as skin and blood - to predict a person’s ancestry and appearance. Scientists scan genes for indicators that influence skin color, eye color and even freckling and plug those markers into an algorithm to generate a composite illustration.

“It’s a high-tech sketch,” Delano said.

On its website, Parabon says the technology, called Snapshot, “is ideal for generating investigative leads, narrowing suspect lists, and solving human remains cases.”

“Armed with this scientifically objective description, you can conduct your investigation more efficiently and close cases more quickly,” the company said.

Snapshot is new to the Philadelphia region. In November, Lancaster County officials used phenotyping to resurrect a cold case from 1992. Dozens of tips flooded the Lancaster County District Attorney's Office since police released an Parabon-generated illustration, according to news reports.

Steele is hoping for a similar outcome in Montgomery County.

“Montgomery County and West Norriton detectives have worked this case hard since the rape five months ago, evaluating and ruling out dozens of people developed of people of interest during the investigation,” he said. “Now we are looking for some help from the public, from anyone who might recognize someone using this additional information.”

Not everyone is excited by the technology. Some observers and lawyers warn that releasing a sketch of a suspect without any witnesses is a dangerous proposition.

Jay Stanley, a senior policy analyst at the American Civil Liberties Union, said that from what scientists have said and written, not enough is known about the link between genes and facial features to rely on the technology to produce a suspect.

“You can lose weight, gain weight, change gender, grow a beard, have plastic surgery,” he said. “It risks ensnaring innocent people in webs of suspicious investigations. It risks playing on existing societal racial prejudices. It risks diverting investigations down wild goose chases.”

Parabon includes a “confidence level” for their predictions in an effort to limit these kinds of conflicts. In the Montgomery County rape case, Parabon is 97.8 percent confident the suspect has light brown or brown skin color and 87.7 percent confident he has brown or hazel eyes. But the face shape, cheeks, nose, forehead chin and mouth are based on sex, ancestry and thousands of genotypes from Parabon's database. Age, BMI and even face shape cannot be determined purely from DNA.

In 2015, Dr. Ellen Greytak, Parabon’s director of bioinformatics, showed NBC News anchor Kate Snow how the technology worked in a report for "NBC Nightly News with Lester Holt:"

"We hope Snapshot’s predictions for this individual prove helpful in the investigation," Greytak said. The suspect's "distinctive ancestry and associated phenotypes should significantly narrow the field of possible suspects."

A $10,000 reward is being offered for any information leading to the identification and arrest of the suspect. Anyone with information is asked to call Montgomery County detectives at 610-278-3368 or West Norriton Township police at 610-630-1701.

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