Common Pleas Judge Rose Marie DeFino-Nastasi sentenced him to 25 to 50 years in state prison under the terms of a negotiated guilty plea.
Timmons, and his attorney, W. Fred Harrison Jr., told the judge that he was high on alcohol, Percocet and Xanax when he accidentally shot Valerie Marie Angeline, 31, in her apartment on 64th Street near Vine, in West Philadelphia.
She had recently move there from Bryn Mawr, where she graduated from Radnor High School.
"You see what drugs do to your brain?" DeFino-Nastasi asked Timmons. "It's like you're living in one big psychotic episode."
Had Timmons gone to trial, he would have faced the possibility of being convicted of first-degree murder and sentenced to life without parole.
Evidence and testimony would have been presented describing how Timmons shot Angeline through an eye, hid evidence in Cobbs Creek Park and returned to stab the still-breathing woman at least 17 times to make it appear that someone else had killed her, Assistant District Attorney Gail Fairman said.
At least one witness would have also testified that Angeline had recently asked Timmons to move out because he was not contributing money toward bills, Fairman told the judge.
Timmons called 9-1-1 to report he had found Angeline's body in the apartment. But police quickly tied him to the crime after detecting a strong odor of bleach in the apartment and finding two empty bleach bottles in the basement, Fairman said.
Two days later, the prosecutor said, Timmons confessed to homicide detectives and led them to where he had hidden bloodstained clothing, a mop, a knife and other evidence in Cobbs Creek Park and at his family's home on Columbia Avenue near 61st Street in Overbrook.