Ex-Marine pleads not guilty to six killings on Orange County A former Marine accused of fatally stabbing six people in an Orange County rampage that spanned nearly three months pleaded not guilty Tuesday. A full-bearded Itzcoatl Ocampo, 23, wearing mustard-colored jail scrubs, appeared distraught and sometimes mumbled to himself. Prosecutors have not disclosed whether they will seek the death penalty. Ocampo, accused of stabbing four homeless men to death between Dec. 20, 2011, and Jan. 13, was taken into custody after bystanders chased him from a Carl's Jr. parking lot where the fourth victim was attacked. Ocampo's arrest that night quickly spread a sense of relief among homeless people who had flocked to shelters during the serial killings. Two weeks later, police announced that a DNA link was discovered between Ocampo's clothing and an Oct. 25 crime scene a mile from his Yorba Linda home, where Raquel Estrada, 53, and her son, Juan Herrera, 34, were found stabbed to death. The accusation freed Estrada's younger son, Eder Herrera, who spent four months in jail on murder charges. Relatives of homeless victims James McGillivray, 53, and Lloyd "Jimmy" Middaugh, 42, attended Tuesday's hearing in Santa Ana. Middaugh's mother, Marie, 65, said she was there because she wanted to see Ocampo in person. But the sight of him made her sick, she said, because she could not comprehend how someone could have killed her 6-foot, 4-inch, 300-pound son. The morning her son was found on the Santa Ana River Trail, she was expecting his usual 7 a.m. phone call, then a visit to her Leisure World home. "That morning, he didn't call," she said. And I knew something was wrong. After the hearing, Lydia Peralta of Placentia hugged Marie Middaugh, and told her she was sorry for her loss. Later, Peralta explained to a reporter, "We are also mourning a loss, too, with our friend Izzy, knowing that his life is over. Any way you look at it, it's tragic. Peralta said she considered Ocampo almost family. One of her daughters was a high school friend of the young man, and she remembers a "happy-go-lucky" teenager who would go to barbecues, often with something like a liter of soda in hand. But when he came back from serving in Iraq in 2009, she said, he was different. He seemed troubled. Like something on his mind," she said. Attorney Randall Longwith said that Ocampo's duties in Iraq included dealing with the wounded and deceased. He also said that, although his client is distant and distraught, he doesn't have a baseline of previous behavior. "I need to see the facts of the case and decide at what point his mental health affects the plea," he said. An appearance is scheduled for March 9 in the case before Judge Francisco Briseno, the most senior judge in Orange County Superior Court.