San Jose police officers responded at 2:17 a.m. to the 4200 block of Stevens Creek Boulevard after the Santa Clara officer saw three men fighting and one of them firing a handgun.
Two of the men were detained at the scene, but the shooting suspect fled the area on foot.
Police searched the area, but the suspect was not located. A handgun was recovered near the scene.
Police said the motive and the circumstances surrounding the shooting are still under investigation. No one was injured in the shooting.
Police described the suspect as a black man wearing a white T-shirt and jeans. A more detailed description was not immediately available.
Santa Clara police arrested one of the detainees for delaying/obstructing an officer after the man attempted to kick out the windows of their patrol car, police said. The second person detained was eventually released.