A jury in California has delivered a guilty verdict in a case that local prosecutors are calling one of the most gruesome in the city’s modern history. On Wednesday, April 1, 2026, 55-year-old Lisa Gonzales of San Francisco was convicted of second-degree murder for the 2018 killing and dismemberment of her roommate, Margaret Mamer.
The conviction follows a chilling investigation that began in June 2018. Mamer, 61, was first reported missing by friends who grew concerned after a week of silence and a history of “escalating tension” between the two women.
According to NBC, when police first questioned Gonzales at their Mission District home on 14th Street, she claimed Mamer had moved to Eureka and even insisted she had helped her pack her things two weeks prior.
However, a tip from a “concerned citizen” led officers to the building’s basement. There, investigators discovered Mamer’s remains inside a blue plastic storage container. An autopsy later revealed a horrific scene: Mamer had been stabbed in the chest and suffered blunt force trauma to her head before her body was sawed into pieces.
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District Attorney Brooke Jenkins addressed the media following the verdict, stating, “This is one of the most gruesome crimes our city has experienced in recent history.”
Evidence presented during the trial shed light on a living situation that turned deadly over an eviction dispute.
A third roommate testified that Gonzales had given Mamer a 30-day notice to move out in April 2018. When Mamer refused to leave, Gonzales reportedly told coworkers who suggested legal eviction methods, “No thanks. I’ll do it my way.”
The details of that “way” were described in haunting testimony from the third roommate. She recalled coming home for lunch in mid-May to find Gonzales barring entry to the bathroom.
By that evening, the witness reported a heavy metallic smell in the apartment and the sound of sawing echoing from the bathroom for hours. The next morning, the smell of vinegar, rotten eggs, and bleach filled the air; a laundry container was missing, and a hacksaw was sitting under the sink.
When the witness asked where Mamer had gone, Gonzales reportedly replied that she had left, “but not the way she wanted to.”
The jury also found true an allegation that Gonzales used a knife during the murder. She now faces a sentence of 16 years to life in state prison. A formal sentencing date will be set at a later hearing.
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