S.F. Driver Avoids Prison Time After Killing Family of 4 in West Portal Crash

80-year-old Mary Fong Lau pleaded no contest to four felony counts of gross vehicular manslaughter.

Published on Feb. 14, 2026

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A woman who prosecutors said killed a family of four while speeding down a residential San Francisco street will likely face no jail time or community service mandates after pleading no contest to four felony counts of gross vehicular manslaughter. Mary Fong Lau, 80, crashed into a West Portal bus stop in March 2024, killing a mother, father and their two young children as they waited for transportation to the San Francisco Zoo.

Why it matters

The case has sparked outrage from the victims' family members, who feel Lau is getting off too lightly despite the tragic loss of life. It raises questions about sentencing guidelines, particularly for elderly defendants, and whether the justice system adequately holds drivers accountable for deadly crashes.

The details

Prosecutors said Lau was speeding at over 70 mph when she crashed her Mercedes SUV into the bus stop, killing Diego Cardoso de Oliveira, 40, his 1-year-old son Joaquim, Matilde Moncada Ramos Pinto, 38, and her 3-month-old son Cauê. The judge said he would likely sentence Lau to 2-3 years of probation, prohibiting her from driving, citing her age, lack of criminal history, and expressed remorse. The victims' family members pleaded for Lau to face home detention and community service, but the judge indicated he would not impose those requirements.

  • The crash occurred in March 2024.
  • Lau changed her plea from not guilty to no contest on February 14, 2026.
  • In July 2024, the surviving parents filed a wrongful death civil suit against Lau.
  • In May 2025, the relatives filed another civil lawsuit asking to void Lau's property transfers.

The players

Mary Fong Lau

An 80-year-old woman who prosecutors said killed a family of four after crashing her Mercedes SUV into a West Portal bus stop at over 70 mph.

Diego Cardoso de Oliveira

A 40-year-old man who was killed in the crash along with his 1-year-old son.

Matilde Moncada Ramos Pinto

A 38-year-old woman who was killed in the crash along with her 3-month-old son.

Judge Bruce Chan

The San Francisco Superior Court judge presiding over the case, who indicated he would likely sentence Lau to 2-3 years of probation.

Samantha Persaud

The assistant district attorney who prosecuted the case and objected to Lau pleading no contest.

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What they’re saying

“The loss of life is incomprehensible.”

— Judge Bruce Chan, San Francisco Superior Court Judge (sfchronicle.com)

“It feels like we have no rights. I feel deeply disrespected by this process. It doesn't feel like this is justice.”

— Denise Oliveira, Sister of victim Diego Cardoso de Oliveira (sfchronicle.com)

“Mrs. Lau has expressed remorse repeatedly. She had to seek psychiatric help.”

— Seth Morris, Defense attorney for Mary Fong Lau (sfchronicle.com)

What’s next

The judge will confirm Lau's sentence at a subsequent hearing.

The takeaway

This case highlights the challenges of holding elderly drivers accountable for deadly crashes, even when their actions result in tragic loss of life. It raises questions about whether the justice system is doing enough to prioritize public safety and provide meaningful consequences for reckless driving.