He joined the Marines to become a killer, police said, and studied anatomy to be swift and effective. And he set a goal — 16 slayings, if possible — of becoming one of America’s prolific killers. “I knew that I had the killer gene,” Itzcoatl Ocampo told detectives.     The chilling portrait of the accused Orange County serial killer emerges in a grand jury transcript that offers the most detailed look yet at the prosecution’s case against the 23-year-old Yorba Linda man and his alleged “serial thrill-kill” rampage that left six people dead, including four homeless men.     Anaheim Police Det. Daron Wyatt told grand jurors that Ocampo’s “demeanor would change, and he seemed to get excited” as he described the attacks to police after his arrest in January.     Ocampo told police he joined the Marines in 2006 with the hope of learning to kill, but he was disappointed that during a six-month tour in Iraq he drove a water truck and never saw combat, according to the transcript of the February grand jury hearing.     “He felt in order to become a real Marine, he needed to kill,” Wyatt testified.
The detective said Ocampo also invoked Charles Whitman, the former Marine who killed 16 people in Texas in a 1966 rampage. Ocampo, the detective said, also aspired to kill 16 people, including the homeless “and people who he believed had wronged him.”   The Iraq War veteran said he targeted the homeless because “they were available and vulnerable,” and that he believed he was performing a public service because their presence was a “blight” on the community. “He did say that he felt it had to be done,” Wyatt said.     The former Marine confessed to killing the first victims, Juan Herrera, 34, and his mother, Raquel Pacheco, 53, whom police had earlier identified as Raquel Estrada, after sneaking into their Yorba Linda home Oct. 25, according to the transcript.     Ocampo said he stabbed Pacheco with a butter knife as she lay on the couch watching TV, finally switching to a second knife when the first one bent, according to the transcript.     When Herrera emerged from his room, Ocampo stabbed him too, authorities said.
“He went on to say that he was hoping one of them would ask him what he was doing there, because he wanted to respond by telling them … ‘I am here to kill you,’ ” Brea Police Det. Philip Rodriguez testified.
According to the transcript, Ocampo said he grabbed bleach from the kitchen and poured it on his victims’ hands to destroy possible evidence, and dipped a butcher knife in Herrera’s blood and put it by Pacheco to stage the scene as a domestic fight.     Police said Ocampo told them he killed Pacheco and Herrera because they had been rude to him, and that Pacheco’s younger son, Eder Herrera, had broken off their longtime friendship. Eder Herrera was originally charged with the slayings, but the charge was later dropped.     Police said Ocampo then turned his attention to the homeless, killing James McGillivray, 53, in a Placentia strip mall Dec. 20. A surveillance video shows the attacker rounding a corner, coming straight for McGillivray as he lay on the pavement, then straddling him and stabbing him.
Police said Ocampo planned the slaying carefully, leaving his backpack, a spare sweatshirt and glasses nearby before putting on gloves and sneaking up on his victim. Police said he retrieved his backpack, pulled a clean sweat shirt over his bloody clothing, then left his bloody clothing in a bag in the hall and washed it at a laundromat the next day.     Several nights later Ocampo said he spotted Lloyd Middaugh, 42, on a bedroll reading a book by a riverbed in Anaheim, according to the testimony.     Ocampo said he waited until the man appeared to fall asleep and then killed him in a roughly five-minute attack.
“As the attack was going on, [Ocampo] said that Mr. Middaugh asked him what he was doing,” Wyatt said. “And he replied that he was there to kill him. He said that he then asked Mr. Middaugh why he was homeless. And Mr. Middaugh replied that he had been homeless all of his life.”     Afte

r the attack, Ocampo said he stopped at a 7-Eleven to buy some beef jerky, which he ate in the parking lot before walking home to his mother and younger siblings.     Police said Ocampo killed Paulus Smit, 57, in a stairway outside the Yorba Linda library Dec. 30, after stealing the man’s bike to make sure he couldn’t escape.     As media attention over the homeless slayings grew, police said, Ocampo seized on a photograph in the Los Angeles Times to select John Berry, 64, who slept by the Anaheim riverbed, as his next victim.
After stalking him for days, police said, Ocampo ambushed Berry in a parking lot Jan. 13 and stabbed him to death. Police said a witness chased Ocampo into a nearby mobile home park, where he was captured.     Ocampo said he believed he deserved the death penalty for the killings, detectives said.
“It is the stuff that movies are made of,” prosecutor Susan Price told grand jurors in seeking the six-count murder indictment. “Because rarely do you find anyone that is so evil, so sophisticated, and so determined to end another person’s life.”