Father Slits Throats of Wife and Mother-in-Law While Twin Daughters Slept Nearby

Authorities say a San Francisco Bay Area father committed a brutal double murder inside his family’s upscale Walnut Creek home — and then allegedly enlisted his mistress to help erase the evidence.

Police say Howard Wang, 43, a software engineer living in one of the region’s wealthiest suburbs, killed his wife, Linlin Guo, and her mother, Beimin Cheng, on the night of September 18 while the couple’s eight-year-old twin daughters were inside the house.

When officers arrived, Wang reportedly greeted them with gunfire — claiming he was shooting at an intruder who had just “fled the scene.” But investigators soon realized the story didn’t add up.

Detectives found both victims with their throats slashed. Wang’s young daughters, still in pajamas, were unharmed but described as “deeply traumatized,” according to police sources.

Inside the home — valued at nearly $2 million — investigators say Wang had attempted to stage the crime scene to make it look like a break-in gone wrong. But evidence quickly pointed back to him.

District Attorney Diana Becton announced murder charges four days later, citing “special circumstances” for multiple killings. “This tragic case is a stark reminder of the devastating toll domestic violence takes — not just on victims, but on entire families,” she said.

If convicted, Wang faces life in prison without parole.

Court filings reveal that Wang and Guo had a turbulent marriage marked by fear and alleged violence. Prosecutors say Guo had tried to reach out to police months earlier but was “prevented from doing so” by Wang.

Records show Wang filed for divorce in January 2024 — only to withdraw the petition that August, the same month he allegedly made threats to kill his wife. He’s also accused of stopping Guo from contacting law enforcement during a separate domestic dispute in January 2023.

A neighbor, who asked not to be named, told local reporters that “the family looked picture-perfect from the outside — a beautiful house, luxury cars, and polite kids. But clearly, something very dark was happening behind those walls.”

The case took an even more shocking turn when police arrested Yan Wang, the alleged mistress, on September 30 — less than two weeks after the murders.

Yan, 45, from nearby Oakland, is accused of destroying cell phones to hide messages between her and Howard Wang, and of breaking into his home the day after the killings to remove or steal evidence.

“She acted with knowledge of the murders and with the intent to help Mr. Wang avoid arrest and prosecution,” prosecutors said in a statement.

Yan Wang has been charged with two felonies — accessory after the fact and first-degree burglary — and a misdemeanor for destroying evidence. She pleaded not guilty during her arraignment.

Walnut Creek residents — used to quiet streets and manicured lawns — are still reeling. “You never think something like this can happen a few doors down,” said one neighbor. “Those poor little girls have lost their entire family in one night.”

The twins are reportedly staying with relatives under protective supervision as the case moves forward.

Howard Wang remains in custody without bail. His next court appearance is scheduled later this month.