Robin Warr Lawrence was 37 years old in 1994 when someone broke into her Virginia home and stabbed her 49 times … killing her and leaving her 2-year-old daughter alone for two days until a neighbor discovered her body.

For years, police couldn’t find a culprit … until new DNA testing led them to a man who claims he would’ve been a serial killer if not for his wife and children.

The whole story’s being laid out in a new episode of “48 Hours” which will introduce the world to Stephan Smerk … the man who last year pled guilty to murdering Robin and was sentenced to 70 years in prison in March 2025.

At the original crime scene in November 1994, DNA evidence was collected — specifically blood from a bathroom towel. DNA science was still in its relative infancy — this is before the O.J. Simpson trial, for example — and the evidence brought back no immediate suspects.

However, Parabon NanoLabs — a company making huge leaps in genetic genealogy and DNA phenotyping — and investigators were able to generate a suspect profile that matched a relative of Smerk’s.

Cops met Smerk outside his home in New York while he was taking out the trash … and, they asked him for a DNA swab which he voluntarily provided. Shortly after he called them and turned himself in for the murder.

According to Smerk, he was an active-duty soldier stationed near Northern Virginia who felt compelled to kill. He left the barracks, chose Robin’s house randomly, broke in and murdered her.

He stunningly told cops … “I honestly believe that if it wasn’t for my wife and my kids, I probably would be a serial killer.” Smerk later moved to the Empire State and lived a quiet life as a software engineer.

After he killed Robin, Smerk told cops he took a shower, got rid of his clothes … then just continued on with his life as if nothing happened. Smerk also told cops he was under the influence of alcohol at the time of the murder.

Robin’s husband asked a neighbor to check on her after not hearing from her for several days … and, when they arrived, the neighbor found the back door open and called for Robin’s daughter. The daughter was treated for dehydration after she was found.