Police in Los Angeles say they have arrested one of two men apprehended after a Halloween shooting on the University of Southern California (USC) campus that injured four people.
Officer Rosario Herrera said the other man they detained is still being questioned by detectives.
None of the injured or the apprehended men are USC students.
Officer Sarah Faden said a weapon was recovered near the shooting scene outside a Halloween party but investigators will have to test it to determine if it was the one used in the attack.
Students were told to shelter in place with a campus-wide alert issued minutes after the shooting on Wednesday evening.
It was lifted three hours later and students were advised classes would be held as scheduled on Thursday.