Santos Castillo Jr., 21

Santos Castillo Jr., 21, a Latino young man, was shot in the abdomen during a large Holloween flyer party in the 17800 block of Arvida Street in Granada Hills about 11:40 p.m. Friday, Oct. 19, and died at 3 a.m. Oct. 20.

He was inside when a man whom police called a documented gang member walked up to him and began arguing. The argument spilled outside onto the sidewalk, and Castillo, who police said was not a documented gang member, was shot. He was from Sun Valley. Detectives need to talk to anyone who was at the party, "but by the time we got there, everyone was gone," said Det. Mike Fesperman of LAPD Devonshire. He can be reached at (818) 332-0537.