How a water bottle, family tree and DNA testing helped solve a 24-year-old murder mystery!

More than 20 years after the brutal murder of Leslie Preer in 2001, the case finally came to a close. Investigators in Montgomery County, Maryland, used tools of modern forensic science — a bottle of water, a family tree, and the evolving science of genetic genealogy — to solve the case.

Eugene Gligor, 45, pleaded guilty to second-degree murder in Preer’s Chevy Chase home. According to prosecutors, the break in the case came not from a new eyewitness or confession, but DNA evidence re-examined using technology unavailable at the time of the crime.

Investigators identified Gligor through investigative genetic genealogy, a technique that allows law enforcement to compare DNA collected at crime scenes with public genetic databases, often used by consumers seeking to learn about their ancestry.

"The method doesn't so much lead directly to the suspect but can point investigators to possible relatives, even distant ones," Sgt. Chris Homrock, who leads the Montgomery County Police Department's cold-case unit, said. 

In Gligor's case, the process began in 2022, when forensic analysts uploaded DNA found at the 2001 crime scene to a public genealogy database. The results matched two women in Romania who had no direct connection to the case but were determined to be distant relatives of the suspect.

Detective Tara Augustin spent nearly two years mapping out the suspect's extended family tree, eventually identifying relatives with the surname "Gligor" living in theU.S. The name rang a bell — a former neighbor had once mentioned Eugene Gligor, an ex-boyfriend of Preer's daughter, in the original case file. That tip became a turning point.

"That was our aha moment," Homrock said. 

With Gligor under suspicion, investigators waited for an opportunity to collect his DNA without alerting him. That opportunity came on June 9, 2024, when Gligor returned to the U.S. from London. Acting on a plan devised with customs officials, Montgomery detectives set up a secondary screening at Dulles International Airport. Inside the room, they left water bottles on a table.

Gligor drank from one of the bottles, unaware it would later provide the evidence prosecutors needed. After he left, detectives recovered the bottle and sent it for testing. The result was a direct match to DNA found under Preer's fingernails and in blood at the crime scene. 

The original investigation began on May 2, 2001, when Preer, then 49, failed to arrive at her job at an advertising production company. Her husband and a coworker entered the home and found signs of a struggle: bloodstains, a toppled table, and a displaced rug. Police later discovered her body in an upstairs shower. An autopsy showed she had been strangled, and her head had been repeatedly slammed into the floor.

Despite collecting male DNA at the scene, authorities in 2001 lacked the technology to make a conclusive match. It was not until the emergence of investigative genetic genealogy — first widely used in the 2018 arrest of the "Golden State Killer" — that the potential to solve such cases became more widespread.

"I believe, 100%, that DNA is the greatest tool ever given to law enforcement to find the truth, whatever that is," Anne Marie Schubert, independent district attorney of Sacramento County, California - where the suspected Golden State Killer was arrested - said.

"Forensic genetic genealogy is the most powerful new law enforcement investigative tool since the development of fingerprint identification," CeCe Moore - a genetic genealogist who helped solve over 270 cases using this method - said.

While the DNA match was a major development, Gligor's defense attorneys argued in court filings that the method used to collect the DNA violated his Fourth Amendment rights against unreasonable searches. They planned to challenge the evidence at trial, but Gligor ultimately pleaded guilty before the court could rule on the motion.

Unlike traditional DNA matching, which relies on criminal databases, this newer technique uses public ancestry platforms to identify suspects' relatives. In Gligor's case, detectives traced his DNA through relatives unaware of his involvement, a technique that bypasses the need for a direct match in police databases.

However, the growing use of this technology has sparked debate about privacy rights and legal oversight. "What we have right now we can call the Wild West. There aren't a lot of rules on the ground," Natalie Ram, a law professor at the University of Maryland, said.

Under the plea agreement, Gligor faces up to 30 years in prison, avoiding a potential life sentence had he been convicted of first-degree murder. Sentencing is scheduled for August 28.