San Diego County Sheriff's Detectives had exhausted all leads to determine whose legs were found in a dumpster in Rancho San Diego in 2003. But two decades later – with the help of public genealogy databases mixed with their own investigative tools – detectives were finally able to crack the case, officials announced Friday.
SDSO used a technique called investigative genetic genealogy to determine in December 2020 that the legs found in a dumpster at an apartment complex in the 1600 block of Hilton Head Court on Oct. 5, 2003, belonged to then 54-year-old Laurie Potter, from Temecula – a woman whom no one ever reported missing.
That's because, according to investigators, only one person knew about her disappearance – her then-husband, now 68-year-old Jack Potter. He was arrested on one charge of murder at his home in Rancho Cucamonga on May 12, 2021, SDSO said.
SDSO did not detail what evidence led them to suspect Potter in his wife's gruesome death but SDSO Homicide Lt. Thomas Seiver said “the investigation revealed substantial and conclusive evidence that Jack had murdered Laurie.”
Get San Diego local news, weather forecasts, sports and lifestyle stories to your inbox. Sign up for NBC San Diego newsletters.
When Laurie Potter's legs were discovered after a 911 call from a worker in the Rancho San Diego complex, there was little evidence to go on. Seiver said the complex was searched for other body parts, but none were found.
An autopsy was able to determine the legs were those of an adult female and that her manner of death was a homicide. But, there was not much else to go off of. And, while detectives tried to follow every lead they could, the case eventually grew cold.
In June 2020, the case was reexamined using investigative genetic genealogy, a technique that merges standard genealogy tracking from sites like 23andMe and Ancestry.com with standard law enforcement investigation techniques.
At the head of that project was SDSO's Cold Case detective Troy DuGal, who learned how to use the technique from the FBI agents and genealogist who solved the Golden State Killer case.
Without knowing yet whose DNA they had, DuGal sent the sample to public genealogy databases to determine if there was a match.
"I then got a familial match of someone who's related to Laurie Potter but very distant – third or fourth cousin away," DuGal said. "We build family trees up and try to get a cross of two members of the family so we can determine the most recent common ancestor – and that may be all the way back to the 1800s. In this case, it was.”
He then had to work his way back down the family tree, calling familial matches to determine if they were close family of Laurie Potter.
"The database, it's not a law enforcement database. I’m using public, ordinary genealogy websites to build family trees, and many times I’ll identify someone, they’ve already been on Ancestry, 23andMe, all these other genealogy websites and they will have a family tree," DuGal said.
At least 20 family members were contacted and interviewed to further progress the family DNA of this still unknown sample. Each person had to give their 100% consent that DuGal could use their family tree, otherwise, he'd have to try again with someone else. In this case, DuGal said not a single person denied his request.
Little by little, the pieces came together. Then, in December 2020, detectives found Laurie Potter's adult son. With his help, she was finally identified as the cold case victim from nearly two decades prior.
But the work was not done. Now, detectives had a new lead and, with it, could restart their standard investigation. Who was Laurie Potter? Who were her friends? What did she do? And, most importantly, what happened to her leading up to Oct. 5, 2003?
While few details of what happened next were released, SDSO is confident they have the right suspect in custody. Jack Potter was booked into San Diego Central Jail on one count of first-degree murder.
“This is a sad moment and it's sad for the family of the victim, and that’s what we care most about, DuGal said. "But on the other hand, the victim’s family – and I've spoken to them – are very happy that one, I identified Laurie – because they thought she was just living somewhere nobody knew. And, they’re extremely happy, once they get over the grief of Laurie being deceased, that we’ve identified and arrested the suspect."
SDSO said it was the first time a law enforcement agency in San Diego County was able to use the investigative genetic genealogy to solve a cold case and make an arrest. The method has been used to close prior cold cases, but in those instances, the suspect was dead at the time it was solved.
"Laurie was never reported as a missing person," Seiver said. "This case would have unlikely to have ever been solved without the use of investigative genetic genealogy."
SDSO said their investigation is not done yet. They'd like to talk to anyone who knew Laurie or Jack Potter anytime from the 80s until now. Anyone with information was asked to contact the SDSO's homicide unit or Crime Stoppers.
Sign up for our Breaking news newsletter to get the most urgent news stories in your inbox.