The couple and the suspect lived at the mobile home park near state Highway 37 and Sonoma Boulevard, police said.
A Vallejo man was killed and his girlfriend was wounded in a stabbing incident early Saturday morning at a Vallejo trailer park, a police lieutenant said.
Davin O'Reilly, 43, suffered a lethal stab wound in the upper torso when he was stabbed around 12:50 a.m. at the Olympia Mobile Home Park, Lt. Ken Weaver said.
He was pronounced dead at Kaiser Permanente Vallejo Medical Center, Weaver said.
O'Reilly's girlfriend, 42, was stabbed in the abdomen and was taken to the John Muir Medical Center in Walnut Creek, Weaver said. She was in stable condition and was scheduled to be removed from the intensive care unit this afternoon, Weaver said.
Police arrested Cameron Wiess, 32, at the mobile home park, Weaver said.
Witnesses said Wiess stabbed the 42-year-old woman with an 8-inch folding knife, then stabbed O'Reilly when he came to her aid at a residence at 108 Mimosa Drive, Weaver said.
Davin was holding a BB-gun style rifle in front of Wiess, and Wiess took away the rifle and stabbed Davin, Weaver said.
All three lived at the mobile home park near state Highway 37 and Sonoma Boulevard, Weaver said.
The incident is still under investigation, but witnesses said a group of people were smoking marijuana outside the mobile home when the stabbings occurred, Weaver said.