A Maryland family is reeling after DNA has linked a woman's ex-boyfriend to her mother's 2001 murder. 

"It’s been a hell of a day," Lauren Preer, Leslie Preer's daughter, told FOX 5 this week. "He was my ex-boyfriend."

Preer told the station that she dated Eugene Gligor, now 44, when she was about 15 years old and their families knew each other.  

Leslie Preer was found dead in her home in Montgomery County's affluent Chevy Chase neighborhood on the morning of May 2, 2001, after she didn’t show up for work that day, the Montgomery County Department of Police — Cold Case Section said in a release on Tuesday. 

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Police said that blood evidence from the scene was submitted to a lab for genetic genealogical DNA analysis and earlier this month Gligor was identified as a match.

"It’s forensic genealogy that helped us get a name or DNA relation to link that to the victim," Assistant Chief Nicholas Augustine with the Montgomery County Police Department told FOX 5. 

"We will go many years, whether it's 20 or 40 years, to find out the answers and hold people accountable for violent incidents that happened in the past," he added.

Gligor was arrested by the US Marshal's Task Force in Washington, D.C., on June 18, and has been charged with first-degree murder. 

Preer said she had never suspected him in her mom’s murder. 

"Not at all," she told FOX 5, adding that she had run into him in the last year. "I’ve spoken to him. He didn’t seem weird and how you could look someone in the eye and know that you committed this crime and act like nothing happened is pretty unreal." 

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Gligor is currently awaiting extradition from Washington, D.C., to Maryland. 

Police have not given a motive for Preer's murder.