Police said Nicholas James Valdez was arrested on suspicion of homicide in the death of David Gonzales. He walked into the jail in South Salt Lake hours after the shooting.
His brother, Donald Valdez, is being charged with obstruction of justice.
Gonzales, 28, was shot in the head early Saturday morning during a party near 900 South and 300 West. His body was found on a sidewalk.
Authorities said although they have made arrests, they still want to talk to others at the party to get a better sense of what happened. There is no motive for the shooting.
Anyone with information is asked to call Salt Lake Police at 801-799-3000.