A cheating husband has been accused of slittinghis wife's and mother-in-law's throats before having his mistress destroy the evidence.

Howard Wang, 43, has been charged with murdering his spouse Linlin Guo and her mother Beimin Cheng at the family home in Walnut Creek, California. The couple's eight-year-old twin daughters were said to be inside the house at the time of the killings.

After cutting Guo and Cheng’s throats, Howard Wang is alleged to have fired two gunshots, and falsely claimed he was shooting at an intruder. His mistress, 45-year-old Yan Wang (no relation), has since been charged with accessory to a crime, burglary, and destroying evidence.

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Prosecutors allege she had tried to cover for him and broke into the home to steal, taking and destroying two mobile phones in an effort to inhibit the investigation. In a hearing on September 23 following Mr Wang's arrest, sheriff’s deputies were forced to intervene after Yan Wang showed up in court and scuffled with one member of the victims’ family.

She arrested by Walnut Creek Police the following day, and booked into jail on September 29. Contra Costa District Attorney's office said she was believed to be in a relationship with Howard. Mr Wang faces life in prison without the possibility of parole if convicted.

Records show Howard Wang had filed for divorce in January 2024, before dropping the case in August the same year. Howard is alleged threatened his wife around the time the application was withdrawn.

Announcing that a second person had been charged in the double murder investigation, District Attorney Diana Becton said: "This case serves as a sobering reminder of domestic violence's far-reaching consequences. Our office will pursue justice with the seriousness and urgency this tragedy demands."

An earlier statement from Walnut Creek Police Department said: "On September 18, 2025, at approximately 11:45PM, Walnut Creek Police officers responded to a 911 call reporting a disturbance with possible gunfire in the 100 block of Kelobra Court.

"Upon arrival, officers discovered two adult women deceased inside the residence. Following the initial investigation, an adult male Howard Wang, who was known to both victims was taken into custody.

"On September 24, 2025, Walnut Creek Police Department Detectives arrested Yan Wang, the girlfriend of Howard Wang, for two counts of Penal Code 32 – Accessory After the Fact.

"She was taken into custody near her residence in Oakland and booked at the Martinez Detention Facility, where she is being held with no bail.