DENVER -- A man accused of raping a woman and leaving her to die in an alley in frigid weather was convicted Friday of first-degree murder and sexual assault of an at-risk adult.

The jury deliberated just more than two hours before reaching the verdict.

Willie Trimble faces life in prison without the possibility of parole. He has not been sentenced.

The 61-year-old victim, Judith Pyle, was working as an usher at the Pepsi Center and had ridden a bus home from work on Dec. 8, 2007, when she was attacked and sexually assaulted in an alley near 35th Avenue and Clayton Street in northeast Denver.

Friends say she was on the ground in the snow for two hours, in 3-degree weather.

The victim's son, Ronald Pyle, was home cooking dinner on the night of the attack. When his mom failed to show, he assumed that she was staying at a friend's house because of the snow storm.

"While I was sitting there waiting and cooking her food and wondering, she was just a block and a half away in the alley screaming for help," he told 7NEWS earlier.

A neighbor finally heard her cries and called police.

Pyle was taken to a hospital, but died from hypothermia.

Trimble also faced multiple charges of sexual assault and kidnapping in a 1997 cold case. In that case, Kimble allegedly grabbed a 34-year-old woman in April 1997 and sexually assaulting her behind a home in the 700 block of East 23rd Avenue. Investigators were led to Trimble through DNA evidence.

Trimble's sentencing date will be set next week when he appears in Denver District Court for a status hearing on the second pending case.