DNA Composite Illustration of PA. Rape Suspect Released

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NORRISTOWN, PA — Montgomery County District Attorney Kevin R. Steele and
West Norriton Township Police Chief A. Dale Mabry released a DNA composite illustration of
the suspect sought in the Norristown Farm Park gunpoint rape that occurred on Aug. 1, 2017.

The composite illustration is a scientific approximation of appearance produced through a
process called phenotyping, which uses the suspect’s DNA sample gathered at the crime scene.

The gunpoint rape occurred on Aug. 1, 2017, between 10:30 and 10:50 a.m., on Stony Creek Road, between Lower Farm Road and Upper Farm Road in Norristown Farm Park. The man attacked the 19-year-old victim from behind and held a black semi-automatic weapon is his right hand. The victim described him as a medium-skinned black male in his 20s or early 30s, between 5 feet 5 inches and 5 feet 10 inches tall, with an average build. On that day, which had a high of 86 degrees, the rapist was wearing a dark-colored hooded sweatshirt.

The DNA sample was sent to Parbon NanoLabs in Reston, Va., which generated a composite
illustration of the suspect through phenotyping. Phenotyping is the process of predicting ancestry and physical appearance from DNA evidence using trait predictions for the subject’s eye color, hair color, skin color, freckling and face shape. These scientific approximations are then translated into an illustration or “Snapshot.”

“Since we have our attacker’s DNA, we know who he is—we just don’t know his name and
where he lives. 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,” said Steele. “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. Now we are looking for some help from the public, from anyone who might recognize someone using this additional information. We are committed to using every available avenue to find this violent criminal.”

The DNA sample from the Norristown Farm Park rape suspect shows that he is of “African
admixed” ancestry: 52.48% European and 45.27% African. According to Parabon officials, it is common for African-Americans to have 10 to 20 percent European ancestry; however, this suspect has a roughly 50/50 mix of African and European ancestry, which is fairly rare and may indicate a recent European ancestor.

The Parabon report and “Snapshot” illustration make predictions about the suspect’s ancestry and appearance. According to Parabon, the suspect has light brown or brown skin color (97.8% confidence level), zero freckling (96.2%), brown or hazel eyes (87.7%) and black hair (96.6%).

The face shape, cheeks, nose, forehead chin and mouth are based on deviations from the baseline based on sex, ancestry and thousands of SNP genotypes. Additionally, all composite illustrations produced by Parabon assume the subject is 25 years old with an average body mass index (BMI) of 22. These are default settings since age and BMI cannot be determined from DNA.

“We hope Snapshot’s predictions for this individual prove helpful in the investigation,” said Dr. Ellen Greytak, Parabon’s director of bioinformatics. “His distinctive ancestry and associated phenotypes should significantly narrow the field of possible suspects.”

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