AUSTIN (KXAN) — Even though the DNA link investigators made between two separate homicide cases didn’t match a specific person, there are still other uses for this DNA evidence.
This week, the Austin Police Department announced DNA found in a June 2024 murder matches the DNA found in a 2018 murder in Bastrop County.
In this year’s case, 34-year-old Alyssa Ann Rivera was found dead in an abandoned house in southeast Austin. In the 2018 case, 28-year-old Alba Aviles was found dead in her car on a Bastrop County road.
Investigators test for DNA matches by entering DNA into something called the CODIS system, which is a collection of local, state and national DNA databases.
While the DNA in these two cases matched with each other in the CODIS system, they didn’t match a person previously identified in the CODIS system, meaning the suspect has not previously been arrested and their DNA has not been entered into the CODIS system.
If a DNA hit doesn’t identify a person, what else can investigators use it for?
“Even though [the suspect] is not in CODIS, detectives can explore genealogy to attempt to find family and try a family tree,” said Sgt. Nathan Sexton with APD’s Homicide Unit. “Additionally, if the suspect is ever arrested for certain crimes, detectives would be notified.”
KXAN got further insight into the uses of DNA from the Texas Municipal Police Association (TMPA).
“The technology and information has changed with forensic genealogy. Now instead of looking through a narrow lens, you’re basically looking through a giant plate ” said Clint McNear, a former detective and now field services supervisor with TMPA. “Now you don’t have to find the contributor of that DNA, I can find a sibling, a parent, a child a cousin, an aunt or uncle.”
McNear also said having the same DNA linked to two separate homicides can help investigators eliminate potential suspects.
“We’re getting hundreds, sometimes thousands of leads,” he said. “It’s as important that I can clear someone as it is that I find someone. If that wasn’t your DNA and you weren’t at the scene of that crime. It’s very likely you weren’t there and weren’t involved in it.”
‘Immediately,’ Detectives say proper notification of DNA match occurred
Once the CODIS system produced a match between the 2024 and 2018 homicide cases, “homicide detectives were notified and immediately reached out to Bastrop County,” Sexton said.
KXAN asked APD about the handling of DNA, because an “oversight” occurred regarding DNA in a case unrelated to these two homicides: the 2019 murder of Gloria Lofton. Raul Meza, called a serial killer by some officials, is charged in her death.
Meza’s arrest affidavit stated that in 2020, a DNA profile obtained from a sexual assault kit for Lofton’s matched Meza’s DNA, but police did not arrest Meza at that time. He allegedly went on to kill someone else four years later.
Police admitted a communication error occurred regarding the DNA hit, which contributed to Meza not being investigated to a greater length at the time.