SAN MARCOS — A man convicted of fatally stabbing his girlfriend in San Marcos was sentenced Friday to 26 years to life in state prison.

Ziyah Jay Patterson, 31, was found guilty by a Vista jury of first-degree murder and a knife-use allegation in the Dec. 26, 2023, killing of 42-year-old Angela Marie Lanway.

Prosecutors said Patterson and Lanway, who were homeless and living behind a local business at the time, got into an argument after Lanway asked Patterson to turn down his music.

Patterson then asked the victim to return a gift he had given her — identified in a prosecution sentencing brief as a blanket — and she threw it at him.

According to the San Diego County District Attorney’s Office, Patterson then beat Lanway and stabbed her multiple times in the head, leaving her with stab wounds to her ear and neck.

He later called 911 and said, “She threw something at me. I was scared. I stabbed her in the side of the head,” prosecutors wrote in sentencing documents.

Lanway was taken to a hospital, where she died.

At trial, Patterson testified that he acted in self-defense, though prosecutors argued he had no injuries and that Lanway had medical issues that prevented her from walking easily or seeing out of one of her eyes.

San Diego County District Attorney Summer Stephan said in a statement released after Patterson’s sentencing hearing, “Too often, circumstances surrounding domestic violence are made even more dangerous when people are living in vulnerable conditions like being homeless, but our prosecutor and law enforcement believed the victim’s life mattered and deserved justice. This was a devastating and senseless loss of life and Angela’s attacker is being held accountable for his actions.”