An Iraq war veteran already accused in the serial killings of four Orange County transients was charged on Monday with two more murders -- the October stabbing deaths of a high school friend's mother and brother.

The additional charges mean that former Marine Itzcoatl Ocampo faces a total of six counts of murder with special circumstances linked to the two October deaths and the slayings of four homeless men in a crime spree that rattled Orange County residents.

Orange County prosecutors have not yet decided whether they will seek the death penalty against 23-year-old Ocampo.

Ocampo, who is being held without bail, briefly appeared on Monday in Orange County Superior Court in Santa Ana, where a judge postponed his arraignment until next month at the request of a defense attorney.

The new charges against Ocampo stem from the murders of Raquel Estrada, 53, and her son Juan Herrera, 34, who were found stabbed to death in their home in October.

On Friday, prosecutors dropped murder charges in that case against Estrada's other son, Eder Herrera, 24, a friend of Ocampo from high school.

Orange County District Attorney Tony Rackauckas has said that Herrera had not been conclusively eliminated as a suspect, citing significant evidence that led to originally filing the charges against him.

Ocampo was arrested in January after he was chased down by bystanders following the stabbing murder of Jon Berry. Prosecutors say Ocampo targeted Berry after the 64-year-old transient appeared in a Los Angeles Times article about the homeless murders case.

Also slain in the string of murders of transients in December and January were James McGillivray, 53, Lloyd Jimmy Middaugh, 42, and Paulus Dutch Smit, 57.

Ocampo served in the Marines from July 2006 to July 2010 and was deployed to Iraq in 2008, according to the Marines.

Court Iraq California Los Angeles