Anaheim Police Dept., File, Associated Press
FILE - This file photo released on Saturday, Jan. 14, 2012, by the Anaheim Police Dept. shows Itzcoatl Ocampo. Southern California prosecutors say Ocampo, already accused of killing four homeless men, will face new charges for the stabbing deaths of a mother and son who lived near him.

SANTA ANA, Calif. — Southern California prosecutors say a man already accused of killing four homeless men will face new charges for the stabbing deaths of a mother and son who lived near him.

Orange County District Attorney Tony Rackauckas says his office plans to file the two new murder charges against Itzcoatl Ocampo on Monday for the stabbing deaths of Raquel Estrada and her son Juan Herrera.

Charges were dropped Friday against Estrada's son and Ocampo's high school friend Eder Herrera.

Herrera was arrested shortly after the October killings in Yorba Linda.

But Rackauckas says that while Ocampo was in jail on suspicion of the series of homeless killings in December and January, DNA evidence was taken from his home and he was linked to the mother and son killings.