Woman found guilty of killing roommate in San Francisco, dismembering her body
Apr 01, 2026
A woman was convicted of second-degree murder Wednesday in the gruesome 2018 slaying of her roommate in San Francisco.
Officials said Lisa Gonzales dismembered 61-year-old Margaret Mamer and stuffed her into a basement storage bin. The motive for the killing was determined to be frustration over
unpaid rent.
Gonzales is facing 16 years to life in prison, according to San Francisco District Attorney Brooke Jenkins. A sentencing date has not yet been set.
When police showed up at a home on 14th Street in the city’s Mission District in June 2018, Gonzales opened the door and invited them in. Officers were trying to contact Mamer. Her friends and family had called police to conduct a welfare check.
“San Francisco police discovered the victim dismembered and in a storage unit of the building in which they had lived,” Jenkins said.
Mamer’s remains were in plastic bags and a bin in the basement of the building. Court documents released when Gonzales was first arraigned described remnants of a body which had been chopped or sawed up and stuffed into oozing plastic bags.
The case circulated through the criminal court system for eight years. Jenkins said it was marked by several delays from the defense – something that’s actually part of a strategy from defense attorneys.
“Sometimes they realize that our cases have very strong evidence and that the best advantage that they can gain is to delay so that memories fade, so that we lose contact with witnesses, so that oftentimes witnesses or the families of victims become very frustrated and uncooperative,” Jenkins said. “So it works to their advantage.”
At the time of her arrest, Gonzales’ public defender, Alex Lilian, said she was frustrated with Mamer over unpaid rent.
“When Ms. Gonzales took in Ms. Mamer, she didn’t know her terribly well,” Lilian said in 2018. “I don’t believe she knew that she had a history of not paying rent. I’m not saying that’s a justification for anything. That’s just what I know so far.”
In a statement Wednesday, Lilian said Gonzales feared she would lose her home, where she had lived with her family since the 1960s, and she snapped.
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