Twenty-year-old Calvin Riley was shot and killed on Saturday while playing Pokémon Go near San Francisco's Fisherman's Wharf neighborhood, the Associated Press reported on Sunday, citing information from the U.S. Park Police.
Riley was killed by an "unknown assailant" while playing the mobile game with his friend near Ghiradelli Square, a popular San Francisco tourist attraction, on Saturday night, the AP reported.
The motives for the killing remain unclear — Sgt. Robert Jansing of the the U.S. Park Police told the AP that none of Riley's belongings appeared to have been taken during the attack.
"From what we know there was no confrontation," John Kirby, a family friend of Riley's, told local outlet KGO. "There was nothing said back and forth. It was just senseless, just came up and shot in the back and ran away for nothing."
"There was a large group of people playing Pokemon and then his buddy started playing, as well," Kirby said. "Calvin got a little bit ahead of his friend and kind of went around a corner."
Investigators believe that because the shooting happened near a busy tourist attraction, there may be witnesses, the AP reported. Officials are encouraging anyone with information about the attack to come forward.