Community Chat

[Mindy D]

A California man, Gregory Paul Vien, age 60, was charged with the 1997 assaults of two women. The assaults occurred  in Alemeda County. DNA evidence was obtained after the suspect threw his Baskin Robbins spoon in the trash. 

The first victim was attacked in May of 1997,  while walking to a transit station after she left work. She was dragged into a secluded spot and then assaulted. The suspect used a knife to cut her clothing.  DNA was obtained from samples left on her clothing. 

In the second attack, in September of 1997, a woman was attacked after being pulled from the bleachers of Livermore High School. Other sources state she was attacked while walking near the school. DNA found at the second crime scene was linked to the DNA found at the first crime scene. 

At the time of the attacks, law enforcement authorities had tried submitting the DNA to CODIS, the FBI’s database of DNA. Upon submission, there was no match, so there was no way to know who the DNA belonged to.

Over 20 years later, cold case law enforcement personnel decided to resubmit the DNA to a genetic lab. They were able to get more complete DNA results this time. They obtained Nuclear DNA, which allowed them to rely on genetic genealogy to try to match the suspect. With genetic genealogy, a DNA profile of a suspect is uploaded into an open source or public database of DNA profiles.

A genetic genealogist is engaged to aid the search. The work involves painstaking research. An unidentified suspect’s DNA is cross referenced to search for relatives of the suspect and then meticulously traced to a pool of relatives with some matching loci of DNA and then the pool is narrowed down to a smaller group of potential samples. Detectives then narrow these down.

Once a suspect emerges, the detectives must obtain a sample directly from the suspect and match it to the DNA from the crime scene before making an arrest. Vien was put under surveillance, with detectives obtaining Gregory Vien’s DNA from his spoon. The spoon was taken to the lab to obtain Vien’s DNA which was then lmatched to the DNA from the crime scenes and then Vein was arrested.