Jon David Guerrero, 42, also pleaded guilty to setting two victims on fire as well as eight counts of attempted murder and assault of other homeless people who survived being beaten in 2016.
Deputy District Attorney Makenzie Harvey said Guerrero will be sentenced to four consecutive life terms in prison plus 143 years. The guilty pleas taken by San Diego Superior Court Judge Ken So cancels a June trial, which would have lasted two months.
Guerrero spoke with a raspy voice through a medical mask as he has the flu. The judge asked him several times to repeat his guilty pleas because he could not speak very well. His sentencing is set for May 1.
Guerrero's parents attended the hearing and spoke with one victim, Michael Papadelis, 58, who survived. Papadelis told them "I think there's finally closure" with the guilty pleas.
"I don't hate Jon," said Papradelis to Guerrero's mother. "I'm happy to be alive."
The first victim who died was Angelo DeNardo, 53, who was attacked where he was sleeping under a bridge near Mission Bay on July 3, 2016. A railroad spike was hammered into his head and his body was set on fire.
Police found DeNardo's faded birth certificate, bus pass, credit card, and driver's license on Guerrero when he was arrested on July 15, 2016.
Shawn Longley, 41, was killed in Ocean Beach the next day where he had been sleeping. His identification was also found in Guerrero's possession. Dionicio Vahidy, 23, was attacked where he slept downtown two days later and died in a hospital.
Molly Simons, 83, was the only non-homeless person attacked and she was struck with an object on her head as she was walking to a bus stop in North Park at 5 a.m. on July 13, 2016. She died two weeks later in a hospital from a skull fracture.
Michael Mason survived after having a railroad spike hammered into his face where he slept in the Midway area, and he was left blinded. He died in July 2019.
Guerrero's attorneys requested he be returned to Patton State Hospital where he was undergoing psychiatric treatment with medication. So granted the request and Guerrero will return to San Diego county jail shortly before sentencing.
Papadelis was beaten by Guerrero on July 15, 2016, in the area of 19th Street and C Street.
Papadelis told reporters he was sleeping outside when he was struck in the face with an object that fractured his jaw and nose at 4:30 a.m. He was blinded in one eye, and both eyes were swollen shut for three weeks.
"His whole life he has suffered mental illness," said Papadelis. "I'm a survivor."
Papadelis said he was no longer homeless. He said he would make a statement at the sentencing.
Harvey said the closest statement to a motive by Guerrero came when one victim asked him why did he attack him. "Because you're a bum," Guerrero told one victim.
Guerrero's first assault came in 2009 when he pushed a homeless woman to the ground and stole her bicycle, according to court records. So determined he was mentally competent to stand trial in June 2019. So also ordered him to stand trial on all 15 counts after a week-long preliminary hearing in November 2019.