Modesto man convicted of 2022 murder after shooting into ex-girlfriend’s car
A Modesto man was convicted last month of first-degree murder for a 2022 shooting that killed another man and left his ex-girlfriend injured, according to the Stanislaus County District Attorney’s Office.
A jury found Matthew Douglas Cook, 42, guilty of murdering 36-year-old Matthew McDonough on Sept. 29, 2022. Jurors also found true allegations that Cook acted intentionally, deliberately and with premeditation, and that he personally and intentionally discharged a firearm, verdict forms show. He faces life in prison when sentenced.
According to prosecutors, the shooting stemmed from Cook’s escalating jealousy after his girlfriend ended their relationship earlier that year. The DA’s Office said Cook repeatedly threatened to harm any man he saw with her.
On the day of the killing, Cook was secretly watching his ex-girlfriend when he saw her leave with McDonough, the DA said. Cook followed them, drove up alongside their vehicle near Mitchell Road and Riverside Drive, and opened fire into the car. A single bullet struck McDonough in the chest.
McDonough was able to pull over before collapsing, which prosecutors said likely prevented the vehicle from crashing and injuring the woman.
Court documents show Cook was originally charged with:
- Count 1: Murder of McDonough
- Count 2: Attempted murder of his ex-girlfriend
- Count 3: Felon in possession of a firearm.
Verdict forms show jurors convicted Cook of murder and of shooting at an occupied vehicle, and found firearm enhancements true. Cook was also convicted of assault with a firearm involving his ex.
Sentencing is scheduled for Jan. 21, 2026.
This story was originally published December 2, 2025 at 3:05 PM.
