The man called the Sacramento County Sheriff's communication center around 2 a.m. PST and told the operator an armed woman had threatened him and he was being forced to follow her car, The Sacramento Bee reported.
The report said communication center workers heard gunshots just before the call was abruptly ended.
Police responding to the scene found a man with multiple gunshot wounds in a vehicle and paramedics pronounced the man dead on the scene.
Police said they detained two women in a vehicle matching the description of a vehicle the victim had given. Police also detained a man in the case.
The names of the victim and the suspects were not reported.