Serial killing suspect's life unraveled after Iraq By appearances, Itzcoatl "Izzy" Ocampo felt a deep affinity for the homeless and needy. Friends and family members said the 23-year-old ex-Marine, jobless and often broke, gave money and food to transients on the street. He raided his brother's belongings to donate to Toys for Tots, and when he found a drunk sprawled on the road, he escorted him home. "He learned it from me," said his father, Refugio Ocampo, 49, who is now homeless and living in the cab of a broken-down big rig in a Fullerton parking lot. I always told my kids, 'If we have it bad, others have it worse.' The younger Ocampo's generosity struck some as compulsive and even reckless. A few months ago, when his destitute family was stranded in Bakersfield and desperate for gas money, he gave a beggar the last $5 in his pocket. "I said, 'Why did you do that?' " his father recalled. Itzcoatl just said, 'Don't you see people are starving?'  But if authorities are correct, Ocampo's apparent kinship for the downtrodden somehow curdled into something more sinister, leaving four homeless men dead in Orange County since late December Ocampo, who is being held on a psychological watch at the Orange County jail in Santa Ana, is accused in the stabbing deaths of James Patrick McGillivray, 53, who was killed in Placentia on Dec. 20; Lloyd Middaugh, 42, was found in Anaheim on Dec. 28; Paulus Smit, 57, in Yorba Linda on Dec. 30; and John Berry, 64, in Anaheim on Jan. 13. The killings were gruesome and particularly violent. Each victim suffered at least 40 stab wounds, police told a victim's relative One man suffered more than 50 lacerations. Police have not said whether they have pinpointed a motive. The specter of a serial killer left the county's homeless on edge for weeks and police canvassed north Orange County, urging transients to seek shelter or stay in groups. Roadblocks were set up in an effort to snare the killer and a reward was offered. The former Marine was arrested Friday when he was chased down by a two men after the latest killing, which occurred outside a fast-food restaurant where the victim was a frequent customer. Ocampo had been staying with his mother and siblings in a rented Yorba Linda house. He was a fixture at the city library, where he spent most days reading and scanning the job listings, his brother said. It was near the library that he killed the third victim, also a library regular, police said. Ocampo's family said the 9/11 attacks inspired him to join the military. When Ocampo went through basic training in San Diego in 2006, he struck fellow Marine Robert Hays as "really motivated" and "gung-ho." But something changed after he returned from a deployment to Iraq in 2008 , those who know him say. Though it did not involve fighting, his job with the Marines' 1st Medical Battalion was a notably grisly one. He was assigned to meet and inspect the wounded - both friend and enemy - when they were flown in from combat zones en route to the hospital. "He came back totally changed," Hays said. It was almost like he didn't care anymore. He'd get fidgety, he'd start shaking, spacing out. You'd see him staring off. Jesus Balbuena, Ocampo's roommate at Camp Pendleton after his return from Iraq, recalled that he would "wake up screaming at the top of his lungs twice a week. He would have flashbacks. When he talked about his family's slide into financial hardship, Ocampo would weep, Balbuena said. After he left active duty in 2010, he returned to Orange County to find his father, who had studied law in Mexico, living under a bridge. His brother, Mixcoatl Ocampo, 17, said his brother moved into the family's rented home but suffered from depression, trembling hands and occasional hallucinations. "He was always paranoid," his brother said. He said he would search the closet and bathrooms of the home for bombs. I said, 'Dude, stop it. You're not going to find anything. You are being crazy.'  This behavior seemed to worsen, his family says, when a close friend from the Marines was killed in combat in Afghanistan in 2010. "He started saying things that didn't make sense," his father said. He said terrible things are going to happen. The end of the world is coming. He started searching for hidden things that weren't there, like guns and knives. He said he urged his son to get help. "For what?" he recalled his son replying. Mixcoatl said his brother was "always applying for jobs" but couldn't get hired. Sometimes, he went to job interviews. He went to Best Buy and Wal-Mart and places like that, but they never called him back. He'd say, 'Why bother?'