Alleged Child Rapist Caught After 33 Years Using Family Tree Technique, Police Say

Police in Australia say they were able to arrest an alleged child rapist this week after almost 33 years thanks to “groundbreaking” investigative techniques using DNA to build a family tree of the suspect.

Gavin Jeffery Durbridge, 54, appeared in court Tuesday on a count of deprivation of liberty and two counts of aggravated sexual assault in relation to an alleged 1991 attack on a 13-year-old boy, WAtoday reports. Durbridge was arrested a day earlier in connection with the incident—the details of which a judge described as being among the worst he’d ever heard.

The alleged assault took place on Oct. 25, 1991, when the young boy was riding his bicycle in the Carine Open Space—a park and recreation area in a suburb of Perth, Western Australia. Authorities say the boy—who has not been named—was traveling to a friend’s house when he was confronted by a man who allegedly threatened the child with a knife before restraining and assaulting him.

The boy reportedly informed police about the incident immediately and a swab was taken from his clothing which was stored for the last 33 years.

“New investigative techniques using genetic genealogy coupled with good old-fashioned detective work led to the result we have today,” Chloe White of the Western Australia Police Force said of the process which led to Durbridge’s arrest.

She added that an investigative genetic genealogy (IGG) team “became involved in this case earlier this year and their research led to a family tree of nearly three-and-a-half thousand people being identified.” “Hard work narrowed down to this day, when the man was arrested by the team,” she added, saying the alleged victim was “elated” with the result of the investigation.

Although the force did not provide a precise breakdown of the process that led police to Durbridge, IGG involves identifying suspects by comparing DNA samples collected from crime scenes with the genetic information on genealogy databases. By finding even distant relatives, investigators can then use other sources of information like birth and marriage records to build up a family tree which, in turn, can ultimately be used to identify possible suspects.

Such techniques were famously used to catch Joseph James DeAngelo , the so-called Golden State Killer who pleaded guilty in 2020 to a string of murders and kidnappings in California in the 1970s and 1980s.

Read more at The Daily Beast.