Investigators in the Southern California city gathered Monday to "compare notes," but so far only said the four incidents appeared to be gang-related, said Lt. Eddie Vazquez.
Three people were left dead, beginning at 9:30 Saturday night when Jose Cerda, 45, was shot by someone in a car while riding a bicycle.
Around 11:30, Isais Garcia Lopez, 24 and an unidentified 18-year-old were hit by gunfire while walking in an alley. Lopez died on the scene, while the teen was able to to escape until he was airlifted to a hospital for surgery.
A few hours later, just before 2 a.m., police found a 29-year-old man with a non-life threatening gunshot wound in the leg not far from where they found shell casings littering the street.
Angel Bravo, 29, was shot while leaving his home around 3 a.m., and died in the street.