(CNN)San Diego police freed a man Monday whom they arrested in connection with the killings of three homeless men.
-- Manuel Mason, 61, in an area near Valley View Casino Center in the Midway district shortly before 5 a.m. on the Fourth of July. He remains in critical condition.
-- Shawn Longley, 41, whose body was found the same day at a park on Bacon Street in Ocean Beach.
-- Dionicio Derek Vahidy, 23, who was attacked in the area of Broadway and State Street last Wednesday. Vahidy died in a hospital Sunday afternoon.