An Iraq War veteran has been arrested in Santa Ana, California, on charges of killing four homeless men. Itzcoatl Ocampo is accused of stalking and killing the four victims over a 10-day period last month. Each of the four was stabbed dozens of times. Ocampo served in Iraq until 2008 and was honorably discharged from the Marine Corps in 2010. Friends and relatives say he returned from the war psychologically damaged and suffered from bouts of depression, trembling hands and occasional hallucinations.