The carjacking was reported at about 4:30 p.m. when the suspect followed a man out of the UPS Store in Mountain Shadows Plaza on Golf Course Drive and pulled a gun on him when he got into his car, according to the Rohnert Park Department of Public Safety.
The suspect got into the passenger seat and at gunpoint demanded the victim drive him to the nearest church. They drove to St. Elizabeth Seton, discovered no one was there, and then drove back to Mountain Shadows Plaza.
The man got out of the car, threatening the victim, and went back to the truck he had been driving and took several rifles out of the truck and put them in the victim's vehicle, police said.
The victim managed to get away and the suspect took off west on Golf Course Drive in the victim's car.
The man was identified with a flyer from San Francisco police as Jeffery Boyce and was confirmed by the victim. Boyce had been reported as mentally ill and in possession of firearms.
Other law enforcement agencies in the area were alerted about the carjacking, while Rohnert Park police searched Boyce's truck and found several hundred bullets, six 30-round magazines, a load-bearing vest and a loaded rifle.
The Central Marin Police Authority received a call reporting an attempted carjacking at 6:51 p.m., where a suspect pointed a rifle at a woman's head. He ran away, and police found him nearby and identified him as Boyce.
Police found the original victim's car nearby with several guns inside.
Anyone with information about the case has been asked to call Rohnert Park police at (707) 584-2630.