According to Vallejo police, the bullets started flying at about 8:15 Saturday night at Crest Ranch Park.
Four people were shot. One of them died. So far, police are not releasing many details about what prompted the shooting or even the relation the victims have to each other.
One neighbor who lives near the park was shocked because she knew the man who died.
"I hear shots all the time," said Geri Santiago. But this time around, "it was really sad because one of the victims was a really nice guy."
Police have not yet notified the family of the 57-year-old victim. He was known as a harmless, if often intoxicated, neighborhood wanderer.
"He came by here quite a bit. In the mornings he used to help me bring out my pit and help me kind of set up in the mornings," said Ron Fluker.
Fluker helps run CJ's BBQ and Fish Restaurant, which is located next door to the victim's favorite liquor store.
Neighbors said the man's 67-year-old female friend was also hit by gunfire.
Santiago said the man who was shot didn't invite trouble. "They're not that type of crowd to be causing problems and starting trouble."
Police described the two other male victims as a 35-year-old and a 17-year-old.
The grandfather of the 17-year-old identified him as Curtis Nelson and said the teenager is expected to survive his wounds.
Police only have minimal information about the gunman.
"There were reports of a black male in a dark vehicle as being the shooter," said Lt. Lee Horton.
Police believe the victims were attending a cookout in the park. They're working on getting further details about the person who pulled the trigger.