SAN JOSE -- Patrick William Brennan sounds like a creepy villain straight from a pulp crime novel.
A registered sex offender and arsonist. Living alone in a camper model called a "Prowler." Unable, authorities say, to control his compulsion to launch yet another fire-starting spree, and yet secretly wanting to be caught.
Only there is nothing fictional about the man who told police he is the firebug who terrorized his own neighborhood just east of downtown by setting a series of blazes over five nights this month. Brennan admitted he torched businesses, a massive industrial warehouse, homes and even a Baptist church classroom twice -- knowingly threatening lives and causing at least $6 million in damage.
Neighbors in his mobile home park describe him as an odd, chain-smoking loner who wouldn't respond to friendly greetings and often was seen listening closely to a portable police scanner he wore around his waist. An ex-girlfriend said she was surprised because she thought he was still in prison.
And when he was finally caught, his cool demeanor proved unsettling to even the most hardened investigators.
"Zero emotions. A scary individual," said San Jose robbery Detective Todd Jennings, who interrogated Brennan. "I've interviewed homicide suspects who have shown more emotion than this guy."
Brennan is behind bars at the Santa Clara County jail, held without bail on 13 felony counts -- 10 of arson and three more of attempted arson -- and facing life in prison. Now, a portrait of a deeply troubled man with a long criminal past is emerging. Not only does Brennan, 48, have a history of starting fires from the Grand Canyon National Park to Santa Clara County's foothills, but he also has a 2001 conviction for sexually assaulting a minor.
Arson and forensic experts who have followed the case say that what they're learning about Brennan fits the patterns of reclusive, emotionally disturbed serial arsonists who start with small fires and escalate to bigger ones -- often for sexual excitement.
Mark Mooney, a private fire investigator and former captain of the San Jose arson unit, said Brennan's personal problems probably are rooted in childhood.
"As he grows up, he's dealing with personality and confidence issues," Mooney said. "He's 48 now and still asking himself who he is."
Brennan declined a request for an interview. But whatever the causes, his alleged arson work left a densely populated, working-class community on edge for more than a week as police flooded the streets searching for the man who set fires between Jan. 8 and Jan. 12.
His criminal past stretches back to the mid-1990s, when he was arrested on a misdemeanor charge for setting fire to forest debris in and around the Grand Canyon National Park. Brennan graduated to setting 16 fires in Santa Clara County's western hills on or near hiking trails in 1999, leading to a year in jail.
After that arrest, Brennan, who worked at a carwash, tried to explain his actions in a jailhouse interview with KTVU.
"Well, actually I'm a fairly nice person, I guess. I'm just someone with problems who needs help," Brennan said, citing learning disabilities and adding that he set fires as a "stress reliever" that had gotten out of control.
He told San Jose investigators last week that he was secretly proud of the earlier "South Bay Arsonist" moniker he gained.
His compulsion would develop a new dimension in 2001 with his arrest for sexually assaulting an underage female relative of his girlfriend at their Sunnyvale home. In a bizarre twist, according to a Sunnyvale Department of Public Safety police report, Brennan moved out of his mother's Campbell home and in with his girlfriend's family even though Brennan's now-deceased father was in prison for sexually assaulting the very same girlfriend. Brennan continued dating her while serving time for the 1999 arsons.
In an interview last week, the ex-girlfriend said she hasn't had any contact with Brennan for years and was puzzled by his arson relapse. "I didn't know he was stupid enough to do it again," she said, adding that she did not want to be named out of privacy concerns.
While Brennan described himself as nice, the ex-girlfriend said sharply: "He's not."
He served eight years in state prison for child molestation and was paroled in 2009. His parole ended three years later without any apparent violations, according to the California Department of Corrections and Rehabilitation.
Investigators said Brennan then laid low, bouncing between motels on Monterey Road and buoyed by a conservator who, tasked with overseeing his ailing mother and him, paid his rent and put a weekly stipend of about $125 into his bank account to help offset his chronic joblessness.
Since May, he has lived at an East San Antonio Street mobile home park, keeping to himself in a 25-foot, beige-and-orange Fleetwood recreational trailer built in 1983, now literally held together with tape.
Pedro Vargas, 28, lives across from Brennan, and said he tried several times to say hello. Brennan would not acknowledge him.
"My only suspicion was that he carried around a radio, the kind you listen to the police and fire," he said.
Park residents were shocked to learn that they lived in such close proximity to an alleged serial arsonist. But they were equally disturbed to discover that a registered sex offender was living in their mobile home park.
Brennan told investigators he ended his run of relative anonymity after last visiting his mother, now afflicted with Alzheimer's and unable to recognize him. The ensuing stress, he said, reverted him to his old and dangerous ways.
His arrest on Wednesday, police said, was set into motion by patrol Sgt. Jason Kidwell, who at the end of a shift last weekend combed through law-enforcement databases, including one of registered arsonists in California. Kidwell came across a photo of a man who lived in the middle of the arson zone and resembled a police sketch and home-surveillance images: Brennan.
The discovery prompted police surveillance of Brennan starting last Sunday, ending with his arrest three days later. Brennan surrendered peacefully and then freely admitted to setting the fires, showing uncharacteristic animation as he physically retraced his steps with investigators and told them how he started each one.
Mooney, the former San Jose arson captain, found significance in his cooperation, saying it satisfies a need to be recognized. Jennings also said Brennan admitted to targeting locations precisely because he knew they had security cameras.
"He said he wanted to get caught," the detective said, "because he wasn't going to be able to stop himself."
Staff writer Mark Gomez contributed to this report.