DNA on Toothbrush Helps Colorado Police Crack 2006 Cold Case 

DNA found on a toothbrush has helped Colorado authorities crack a 16-year-old murder case.

Earlier this week, authorities in Aurora charged Salvador Hernandez-Morales, 45, with first-degree murder, felony murder and sexual assault in the 2006 killing of Francisca Perea-Dominguez.

Hernandez-Morales was linked to the slaying after his DNA found on a toothbrush matched semen found at the crime scene.

Hernandez-Morales and Perea-Dominguez, 42, were roommates at the time of her death.

The case came to light on July 1, 2006 when friends found Perea-Dominguez's body lying on her back on the bedroom floor of her apartment. She had been stabbed in the abdomen and sexually assaulted.

A neighbor of Perea-Dominguez's told police that she had heard "a lot of 'bumping' and running through the apartment above her," according to a probable cause affidavit obtained by PEOPLE. "[Witness] said it sounded like people struggling or wrestling."

The neighbor allegedly told police she also saw Perea-Dominguez's roommate, who was later identified as Hernandez-Morales, leave the apartment around 1 p.m.

Police later tracked down his employer and learned that he had not shown up to work shortly after her death and likely had left the United States for Mexico.

"He was always a person of interest," Eric Ross, media relations director with the 18th Judicial District Attorney's Office tells PEOPLE.

Additional DNA testing of items belonging to Hernandez-Morales helped crack the case.

"In the last year additional testing was done and we were able to get a positive link on this DNA from a toothbrush that had been found in the apartment and had been collected and preserved as evidence and that positively matched the semen sample that was originally collected from the deceased victim's body," says Ross. "That evidence had been preserved combined with new DNA testing put the connection together that this was in fact the suspect."

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Ross says investigators believe that Hernandez-Morales is currently living in Mexico.

"We are asking the public's help to give us a specific location," he says. "The extradition process is several months away."