It happened around 9 p.m. Monday on La Mesa near San Simeone. Authorities say a man shot at the four victims in the garage of a home.
One person died at the scene. The other three victims were taken to Modesto area hospitals and they're expected to survive.
Authorities say the suspect was able to get away on foot.
"Some of the witnesses have been uncooperative as we investigate this case. At this point we do believe this incident is gang related," said -Ray Reyna, Los Banos Police Commander.
Police say witnesses reported seeing a male in dark colored clothing running from the area after the shooting. Anyone with information about this incident is asked to contact Detective Eduardo Solis at (209) 827-7070 ext. 137.
The victim's identities have not been released.