Police say DNA evidence linked a 16-year-old suspect to a sexual assault and murder that happened in February of this year.
Phoenix police report that on November 16 they arrested a 16-year-old boy who was already in custody on other charges, for the murder of a 54-year-old woman.
On February 3, she was found in a walkway between two fences near 19th Avenue and Camelback Road. She was allegedly beaten with a rock and sexually assaulted.
DNA evidence from the scene was analyzed and found to be that of a juvenile suspect who was already in jail for aggravated assault and voyeurism.
When interviewed, the defendant initially denied being there at all.
After being confronted with the DNA evidence, he reportedly told investigators that he was fleeing from police when he came across the woman who was already unconscious and bleeding.
He said he found a rock with blood on it and threw it over the fence and because "he did not know when he was going to have sex next" he sexually assaulted the woman.
He said she moved her head, but he was unsure if she was breathing at the time.
He has been charged with sexual assault and first-degree murder.