Suspect in attacks on homeless had long history of mental illness, criminal convictions

Suspect in attacks on homeless had long history of mental illness, criminal convictions
Jon David Guerrero is accused of killing three homeless men in a series of attacks in San Diego. The judge requested that the defendant's face not be shown. (David Brooks / San Diego Union-Tribune)

It was early July and a serial killer was attacking homeless men in their sleep.

Patrick Brady walked past a surveillance photo of the suspect tacked up near the elevators in the lobby at Alpha Square, an East Village apartment complex for homeless and low-income people. When the elevator doors opened, Jon David Guerrero walked out.


The 39-year-old, who mostly went by his middle name, would later be arrested, accused of using railroad spikes and a hammer to brutally kill three homeless men and critically injure two others in the 12-day spree of attacks.

That day in early July, Brady entered the elevator. As the doors closed, Guerrero suddenly stuck his head into the elevator and jumped back inside. He had been acting strangely over the last few weeks and was covered in sweat, Brady said.

"Either he was high or he had just gotten done with one of those killings," said Brady, 55.

San Diego's Metro Arson Strike Team and SDPD homicide team gather evidence from the sidewalk and grassy area where a homeless person was attacked in downtown San Diego.
San Diego's Metro Arson Strike Team and SDPD homicide team gather evidence from the sidewalk and grassy area where a homeless person was attacked in downtown San Diego. (John Gibbins / San Diego Union-Tribune)

Since that elevator ride, Brady hasn't shaken the feeling that Guerrero was the killer police were after.

Guerrero, who will be evaluated by a court-appointed psychiatrist to determine if he is mentally competent to stand trial, seems to have led a reclusive life, troubled by crimes and mental illness.

A Coronado native, Guerrero's grubby getup in high school led to the nickname Grubbit. Former Coronado High School classmates said he was often shoeless, shirtless and dirty. He liked to surf and hung out with people who smoked pot and did other drugs, old classmates said.

After high school, Guerrero, who graduated in 1995, was in and out of Coronado until he moved away around 2000. Before he left, he had a child with a Coronado woman three years younger than him. Former classmates said he's never been a part of the child's life.

The woman did not respond to requests for an interview.

Guerrero's mental illness took full hold of him when he was about 22, according to court records. It also marked the onset of his criminal history. In cases from 1999 to 2001, he was convicted of burglary, grand theft and possession of stolen items.

Then, in 2008, he pleaded guilty to charges of burglary, grand theft and possession of marijuana and narcotics paraphernalia. Kathleen Guerrero wrote several letters to the court, saying her son didn't do well on probation because he had trouble following directions and keeping track of time and appointments.

She tried to get him psychiatric treatment in jail, expressing concerns that, without it, he would revert to previous self-destructive behaviors.

Guerrero was again arrested in 2009 and pleaded guilty to robbery for knocking down a homeless woman and stealing her bicycle several times. While on probation, he violated the conditions, was found not mentally competent and sent to Patton State Hospital.

In arguing for a lesser sentence, his attorney wrote that Guerrero hears "good and bad voices" when his medication wears off, but that he could live a normal, productive life on appropriate medications.

Records show mental health cases filed in 2008, 2009 and 2011. Court records say Guerrero suffered from schizophrenia and was considered disabled. At one point, he was receiving monthly injections of Haldol, a type of anti-psychotic medication.


Guerrero has lived in an independent living facility and, more recently in downtown San Diego. He lived at Hotel Metro, a low-income housing project, for about two years. Residents there dubbed him "Farmer John" because he grew marijuana in his room. At the time he had a vehicle, provided by his sister, and seemed content.

Brady, who considered Guerrero a good friend at the time, said he started keeping to himself when residents at Hotel Metro were relocated to Alpha Square, on 14th and Market streets, upon its completion in January.

Residents there described Guerrero as a recluse who didn't make much of an impression.

Dameon Ditto met Guerrero at Hotel Metro, where the two only greeted each other in passing. It was at Alpha Square that the fifth-floor residents became relatively close, particularly after Guerrero began taking Ditto's art classes, which are free to residents, in April. Ditto described Guerrero's art as "dark."

His artwork depicted "skeletons, black mountains ... Some stuff that scared me after the fact," Ditto said. "I didn't really think much of it at the time."

Guerrero showed a particular creative interest in rocks, turning beach stones and shells into Flinstones-like car figures, Ditto said.

To fashion the handmade cars, Guerrero presumably used a large hammer-like tool Ditto saw him carrying.

"I figured he was using that to chip away rocks," Ditto said.

Last week, Deputy Dist. Atty. Makenzie Harvey said Guerrero is suspected of using a hammer and railroad spikes to kill or maim the five victims while they were sleeping.

On July 6, Angelo DeNardo, 53, was found dead with spikes driven into his head and chest, Harvey said. DeNardo was then torched.

The next day, Manuel Mason, 61, had a railroad spike driven into his sinus cavity in the Midway District. He survived but was rendered blind, Harvey said. Less than two hours later, Shawn Longley, 41, was slain in Ocean Beach.

On July 6, Dionicio Vahidy, 23, was attacked in downtown San Diego. Witnesses heard loud noises and saw a man set another on fire. Vahidy died three days later.

The last victim in the series was found July 15 in Golden Hill, where a 55-year-old man was critically injured. A railroad spike was found near the site of the last three crimes, Harvey said.

An hour after the last attack, officers found Guerrero and arrested him. Police found a hammer, railroad spikes and the identification of two of the victims in the backpack Guerrero was wearing.

That day, detectives spent hours combing through Guerrero's studio, collecting bags of items, Alpha Square residents said. Harvey said police found a bucket that contained rocks, railroad ties and other spikes.

Bob McElroy, executive director of the Alpha Project, a homeless-services organization that runs Alpha Square, said residents were unnerved and dismayed to learn someone in their circle was arrested.

Perhaps no one was more affected than Guerrero's mother, McElroy said, describing her as a homeless advocate.

"She was there all the time, getting him food, giving him cards for Albertson's across the street," he said. "He not only murdered three people, he killed her too. She's devastated."

Guerrero's parents did not respond to requests for an interview.

McElroy said that extra outreach teams worked with the homeless community to identify the killer, including plastering pictures inside Alpha Square, all while the suspect was right upstairs.

McElroy described Guerrero as quiet and polite and compared him to "the Jeffrey Dahmers and the Ted Bundys of the world."


"Unassuming, non-confrontational," he said. "They are always the last ones you would think. People were totally shocked."

Hernandez and Winkley write for the San Diego Union-Tribune.