DNA And A Bloody Hammer Help Cops Make Break In Pennsylvania Gunpoint Rape Case

Mason Hall is accused of taking a young woman by gunpoint away from a park's walking path one summer morning and sexually assaulting her.

By M.L. Nestel
Digital Original
How To Use DNA To Crack A Case

Forensic testing led detectives to bring a 19-year-old man into custody for a brutal sexual assault at gunpoint that occurred back in 2017.

Mason Hall is accused of ambushing a 19-year-old woman from behind at Norristown Farm Park in Pennsylvania on the morning of August 1, 2017 and pointing a black semi-automatic gun at her head before he “forced her into a secluded pasture off of a walking path,” authorities claim in a Norristown Police Department release

Once out of sight from any passersby, Hall, then 17 and allegedly clad in a dark hoodie despite the 86-degree heat, sexually assaulted the woman from behind, authorities claim.

Investigators were thus initially limited as the victim couldn't provide a detailed description of her attacker, but DNA evidence was able to be recovered from the scene.

That evidence is what led authorities to track down Hall and pin him to the sexual assault, the release explains.

“Since we had our attacker’s DNA, we always knew who he was, but it took 27 months of high-tech scientific efforts and thousands of hours of old-fashioned police work to track down this violent criminal and make this arrest,” said Montgomery County District Attorney Kevin Steele. “Rapes and sexual assaults where a gunman attacks an unknown victim are, thankfully, rare in Montgomery County, and we used every avenue available to solve this violent crime.”

Mason Hall Pd

Rigorous “phenotyping analysis” performed at an out-of-state lab helped authorities generate a DNA-generated composite illustration, and the image mimicked the suspect’s likeness.

At the time, Steele called it “a high-tech police artist’s sketch,” according to The Pottstown Mercury newspaper.

“This illustration produced more tips but still we did not have our attacker,” Steele said.

Detectives also caught a break in the case when they found a bloody hammer Hall allegedly admitted to using to break a car's headlamps in an unrelated matter back on Sept. 23, 2017, the publication reported. The blood from the hammer was analyzed with the DNA from the sexual assault. 

“The DNA from the bloody hammer and the DNA from the sexual assault linked up,” Steele explained.

Hall was brought taken into custody by police on October 18 at his home in Norristown, slightly more than a mile from where the assault took place. 

Hall was hit with several charges including involuntary deviate sexual intercourse, sexual assault and terroristic threats. 

The accused attacker remains in the Montgomery County Correctional Facility. 

He is due back in court on Friday for a preliminary hearing. 

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