The same defendant accused in a Walnut Creek double homicide also helped set up an earlier killing tied to his girlfriend, prosecutors say.
MARTINEZ, Calif. — When Contra Costa County prosecutors added a third murder charge against Howard Wang last month, they did more than accuse him in another killing. They widened a case already marked by domestic violence allegations, children inside a home during a deadly attack and claims that evidence was destroyed after two women were killed.
The added charge accuses Wang, 43, in the June 8, 2024, shooting death of Chengli Li in San Gabriel. Prosecutors say Li had been the romantic partner of Yan Wang, whom they identify as Howard Wang’s girlfriend. Howard Wang was already facing charges in the Sept. 18, 2025, killings of his wife, Linlin Guo, and her mother, Beimin Cheng, in Walnut Creek. Together, those allegations frame the case less as a sudden collapse and more as a widening circle of violence with intimate relationships at its center.
Public records in the Walnut Creek prosecution had already pointed to earlier trouble. Prosecutors accused Wang of making criminal threats against Guo around Aug. 31, 2024, and of preventing her from reporting a crime to police on Jan. 7, 2023. Local reporting said he had been arrested that day on domestic violence-related allegations. Those accusations remain separate from the homicide counts, but they are important because they show investigators were examining a pattern that predated the killings. District Attorney Diana Becton, in earlier statements on the Walnut Creek case, said the deaths showed the far-reaching consequences of domestic violence for victims, families and the community.
The Walnut Creek killings themselves added another layer of shock because of where and how they happened. Police were called to the family’s home on Kelobra Court at about 11:45 p.m. after reports of a disturbance and possible gunfire. Officers found Guo and Cheng dead inside. Prosecutors later said Wang slit their throats and then claimed he had fired at a fleeing intruder. Another adult and two children were inside the home at the time and were not injured. Guo was the mother of twin girls, and local coverage later described the grief that spread through relatives and the community after the killings. Wang was arrested after the initial investigation and has remained in jail.
Authorities say the violence did not end with the deaths. Yan Wang, 45, of Oakland was charged in September 2025 with accessory after the fact, first-degree residential burglary and destroying evidence. Prosecutors allege she helped Howard Wang avoid arrest, entered the residence the day after the killings with intent to commit larceny and destroyed cellphones so evidence would not be produced. That filing shifted public attention from the homicide scene itself to what investigators say happened afterward, raising questions about how much help Wang received once police had begun investigating. Prosecutors have not accused Yan Wang in the killings themselves, but they have said she is tied to both the Walnut Creek case and the relationship at the center of the San Gabriel charge.
The newly filed murder count reaches back to the earlier death of Li, 41. Prosecutors say Howard Wang and Demarques James Pearl, 33, planned the killing in Contra Costa County and drove south on June 7, 2024. Li was shot the next day outside his San Gabriel apartment. Authorities allege Pearl was the gunman and Wang was the getaway driver. By tying that shooting to the later Walnut Creek killings, prosecutors are signaling that they believe the case was driven by decisions made over time, not by one moment. What remains unknown is how much of that theory will be laid out in open court at the arraignment stage and how the defense will respond once the joined prosecution advances.
The legal path ahead is now taking shape in Martinez. Contra Costa County says Li’s killing will be prosecuted with the Walnut Creek case because the alleged planning happened there. Pearl’s arraignment was reset for April 1 after defense lawyers asked for more time. Howard Wang’s arraignment on the added charge was reset for April 14 at 1:30 p.m. If the court keeps the joined structure in place, prosecutors will be able to present a single case that spans two counties, multiple defendants and several layers of alleged conduct before and after the deaths.
The case stands now as both a homicide prosecution and a record of damage left around one family. The next public test of prosecutors’ theory is set for the April court dates in Martinez.
Author note: Last updated April 20, 2026.