Las Vegas NowLas Vegas Police Solve Cold Case Murder of Child

Las Vegas Police Solve Cold Case Murder of Child

Police say they've solved a murder case that's 15 years cold. Detectives used old DNA evidence and a new sex offender database to track down a suspect in the rape and murder of 7-year-old Diana Hernandez.

Police say Gregory Wallen is the girl's killer. In 1992, two years before the Hernandez murder, he was arrested for sexual assault in Pahrump. That case had not been fully decided by 1994 and there was no sex offender database then.

Detectives scoured the area around the Sandpiper Apartments looking for suspects. What they didn't know was that Wallen actually lived in the same apartment building as the Hernandez family. He even participated in the search for her body.

Wallen finally registered as a sex offender in 1999, allowing police to match his DNA with DNA found on Hernandez. His fingerprints at the scene erased any other doubt for detectives.

"We were able to make a positive match on our suspect who had been out there for approximately 15 years," said Metro Lt. Lew Roberts.

Wallen was arrested at his home in Pahrump. He faces charges of sexual assault of a minor and murder.