Alleged mistress charged in Walnut Creek double murder case

(KRON) — A woman was having a romantic affair with a Walnut Creek man when he allegedly murdered his wife and mother-in-law, according to investigators.

The accused mistress, 45-year-old Yan Wang of Oakland, will make her first court appearance Tuesday afternoon. Prosecutors charged her with helping cover up evidence from a double homicide on September 18 in Walnut Creek.

Her romantic partner, 43-year-old Howard Wang, is charged with murdering his wife, Linlin Guo, and his elderly mother-in-law, Beimin Cheng, prosecutors said. “Howard Wang was married to Linlin Guo but was in a romantic relationship with Yan Wang at the time of the murders,” the Contra Costa County District Attorney’s Office wrote.

Yan Wang and Howard Wang are not related, prosecutors clarified.

Police said both victims were slain inside the married couple’s Walnut Creek house on Kelobra Court. When officers arrived at the home and found the bodies, Howard Wang and two young children were still inside the house, according to police.

“What happened inside of that home has left the family shattered, and left the community grieving. My heart goes out to the loved ones of the victims,” District Attorney Diana Becton said.

According to prosecutors, the suspected killer’s lover destroyed cellphones to cover up evidence on the same day of the homicides. The following day, Yan Wang broke into the married couple’s house, entered the crime scene, and stole items from the home, court documents state.

The district attorney’s office wrote, “Yan Wang allegedly aided Howard Wang with knowledge following the murders and with intent to help him avoid arrest, trial, conviction, and punishment for killing his wife, Linlin Guo, and her mother, Beimin Cheng.”

Yan Wang is charged with accessory after the fact, destroying evidence, and burglary, court records show.

Investigators uncovered evidence that Wang’s alleged domestic abuse against his wife dated back to 2023, court documents show. In the summer of 2024, the husband made death threats against Guo, and in January of 2023, he prevented his wife from reporting a crime to police, prosecutors said.

Howard Wang is scheduled to be arraigned on October 3 to enter a plea. If convicted, he could face life in prison without the possibility of parole.