A San Francisco woman who was convicted in April for the 2018 murder of her roommate, was sentenced on Monday to 31 years to life.

It's case that District Attorney Brooke Jenkins called "one of the most gruesome crimes our city has experienced in recent history." Lisa Gonzales, who was 47 years old at the time, was arrested after police came looking for her roommate, 61-year-old Margaret Mamer, who had gone missing after friends had heard there was tension between the two women about Mamer refusing to move out.

Gonzales, who had grown up in the apartment at 255 14th Street, was the master tenant, and had been charging Mamer $400 per month since mid-2017 to rent a room there. The women had a third roommate, as well, but Gonzales was apparently unhappy with Mamer as a roommate, and had given her 30 days notice to vacate in mid-April 2018.

Investigators found that Gonzales had been openly complaining to coworkers about Mamer and her refusal to move out, and had said chilling things in response to legal advice from coworkers like, "No thanks, I’ll do it my way."

Then, on May 15, the third roommate came home on her lunch hour and was told by Gonzales not to go into the bathroom. The roommate testified that she smelled the metallic smell of blood throughout the apartment and heard sawing noises from inside the bathroom, which was followed by the strong smell of bleach.

When she asked Gonzales what had happened to Mamer, Gonzales reportedly said that she had left, "but not the way she wanted to."

Gonzales would later tell police that she had helped Mamer move to Eureka on May 15 and hadn't seen her since.

Friends of Mamer told police that Mamer had gone missing, and that she and Gonzales had been at odds. And then an anonymous tip came into the SFPD on June 2, 2018 about a murder and dismemberment taking place at the apartment.

When police visited Gonzales at the apartment, they ultimately made their way to a storage locker in the basement, where they made the gruesome discovery of Mamer's dismembered remains in a "viscous liquid" that was "covered in maggots" inside a blue plastic bin. Police say the found Mamer's limbs placed on top of her head and torso, and they found a hacksaw under a sink the building's laundry room.

Mamer's cause of death was determined to be "sharp force injuries" to her face, head and chest, and there was injury to her heart that suggests a stabbing. Investigators also found blood-spatter evidence in the apartment's bathroom despite Gonzales's cleanup efforts.

Gonzales, who is now 55, was convicted in April 2026 of second-degree murder by use of a deadly weapon — it's unclear why this wasn't considered a first-degree murder case. It's also not clear why it took eight years to bring the case to trial.

In a statement Monday thanking the jury, DA Jenkins said, "The court’s sentence will ensure that Ms. Gonzales is held accountable for this heinous crime. While the victim’s family and friends had to wait far too long for this day to come, we are grateful for their trust in our office and the team on this case to deliver justice."

Previously: 8 Years on, SF Woman Convicted of Grisly Murder and Dismemberment of Roommate Who Wouldn't Leave