SAN FRANCISCO—On June 11, a jury found a local 51-year old resident guilty of first-degree murder. The case dates back to February 2013.

Albert Trejo and his girlfriend, Cecilia Zamora, were living together with additional roommates in San Bruno when the incident occurred. On February 13, 2013, Trejo called another resident in panic, saying that his gun went off by accident.

When the residents came home, they found Trejo doing laundry. When they asked him about the incident, he told them that he had gotten into an argument with Zamora and that she had left.

That was the last day that Cecilia Zamora was seen. Zamora’s mother reported her daughter had disappeared a few days later.

On April 26, 2013, Cecilia Zamora’s body was discovered at a Pacifica apartment complex. The cause of death was a single bullet to the back of the head, according to authorities.

Trejo was found guilty of all charges, including possession of a firearm by a felon. He faces a sentence of 91 years to life in a California state prison. He will be sentenced on September 4, 2015, and remains in custody without bail.