Officers responded to a report of shots fired in the 10300 Murtha Drive in East San Jose at about 1:05 a.m., Sgt. Jason Dwyer said.
When officers arrived, they located a large party that was breaking up, and found a car that was believed to be associated with the call, Dwyer said.
A nearby officer performed a traffic stop at White and Story roads, according to Dwyer.
Dwyer said that the officer conducting the stop saw a male, believed to be 17 years old, inside the car suffering from several gunshot wounds.
He was transported to a hospital where he was pronounced dead shortly before 2 a.m., Dwyer said.
The name of the victim has not yet been released.
No suspects have been identified or apprehended, and the motive of the shooting remains unknown, according to Dwyer.
The homicide marks the 28th in San Jose this year.