In 1986, there were three sexual assaults in and around Lawrenceville, Georgia. The Lawrenceville Police Department responded to each incident and began collecting evidence and investigating. Traditional STR DNA profiles were developed from forensic evidence collected in the sexual assaults, which showed all three crimes were committed by the same man. Upon entry into CODIS for comparison to known offenders, there was no match to a known individual. Despite an exhaustive investigation, no suspect was identified and the case went cold.
In 2025, investigators teamed with Othram to leverage identity inference, a process that enables investigators to identify individuals from DNA evidence, even when there is no known reference sample to initially compare against. Officials with the Georgia Bureau of Investigation Cold Case Unit and the Lawrenceville Police Department worked together to submit forensic evidence to Othram's laboratory headquartered in The Woodlands, Texas.
At Othram, scientists reviewed details of the case, determining that advanced DNA testing could help to identify the suspect. Othram scientists worked to develop a DNA extract from the provided evidence, using Forensic-Grade Genome Sequencing to build a comprehensive SNP profile for the suspect. This SNP profile powered a forensic search led by Othram's in-house forensic genetic genealogy team, resulting in new investigative leads about the suspect's identity.
Using this new information, a follow-up investigation was conducted leading investigators to potential relatives of the suspect. Reference DNA samples were collected from a relative and compared to the DNA profile of the unidentified suspect. This investigation led to the positive identification of the suspect, who is now known to be Glenn Daniel Plybon, age 60, of Carlton, Georgia. On March 18, 2026, Plybon was arrested and charged with three counts of rape and booked into the Gwinnett County Jail.
This investigation is active and ongoing. Anyone with information is encouraged to contact the GBI Office of Special Investigations at 404-239-2106. Anonymous tips can also be submitted by calling 1-800-597-TIPS (8477), online at https://gbi.georgia.gov/submit-tips-online, or by downloading the See Something, Send Something mobile app.
This is the 29th publicly announced case in the State of Georgia where officials leveraged Othram’s identity inference pipeline. Explore other cases on Othram’s website.
Republished courtesy of Othram