Desperate to catch a firebug terrorizing San Jose, and with little more than a grainy surveillance video and a rough composite sketch to help, a police investigator caught a break.

Using the state's arson registry, Sgt. Jason Kidwell noticed that a man with a long history of igniting blazes - including in Grand Canyon National Park - lived in the same area east of downtown where a dozen fires had broken out since Jan. 7, damaging homes, a Baptist church and a huge industrial warehouse.

Police started watching the man, 48-year-old Patrick William Brennan, on Sunday. They didn't see him start any fires by Wednesday, when they raided his home.

There, they found evidence that Brennan was the firebug, officials said Thursday as they announced that the frightening spree was over. Brennan, who is also a registered sex offender, was arrested on suspicion of two counts of arson, and jailed on $1 million bail.

Residents of the targeted area were ecstatic as the news spread. They had responded by forming watch patrols - and even watering down their homes, fences and other property with garden hoses. But Thursday, the fear that had permeated the area turned to relief.

"We've been praying he would turn himself in, but we're just relieved that he's been caught," said Sandra Chavira, 52. "It's concerning that he was from the area, but we're just relieved and feel blessed."

Victim relieved

Nearby, Stan Rubin stood outside the home that he and his wife, Cathy, had bought in 1991 and renovated ever since.

Gutted by flames on Jan. 8, it is now surrounded by a chain-link fence, with a tarp covering the front of the structure and the roof. The windows are boarded up, and black marks above them show where flames licked the house.

"We're relieved that they got the guy off the streets," said Stan Rubin, 63. "Ours was one of the first houses to be burned. We've put in 22 years of work on this place."

He added, "We have good days and bad. I'll be satisfied if he never gets out of jail."

Police believe Brennan is responsible for at least 12 fires. One five-alarm inferno, on Jan. 9, destroyed a huge industrial warehouse near the corner of North 28th and East Julian streets that housed construction-related companies. The blaze prompted a school closure and a call for nearby residents to shelter in place.

At least two houses suffered major damage, including the home of a couple, Sharon and Vince La Vigna, who had to be rescued early Saturday morning before the roof collapsed. Supporters were trying to raise money Thursday to help the couple, saying they lost their fire insurance a few years ago.

A portable classroom behind Greater St. John Baptist Church at 1230 E. San Antonio St. was struck twice, ruining the structure.

Total damage was "in the millions," said Assistant Police Chief Edgardo Garcia, who at a news conference described Brennan as "forthcoming" before he was booked into jail. Garcia said his department is "extremely certain that we have the man responsible."

Sex offender

According to state records, Brennan was forced to register as a sex offender after convictions for sexual assault and battery. Details of the case were not provided, but records show he was imprisoned in 2001, paroled in 2009 and discharged from parole in September 2012.

In 1999, The Chronicle reported that Brennan, who then lived in Sunnyvale and worked at a car wash, was arrested on suspicion of setting 16 fires in the South Bay - the case that landed him on the state's arson registry. The fires that spring and summer were set along trail sites in or near San Jose, Los Gatos and Cupertino.

Brennan had already been labeled an arsonist after being arrested for setting a number of fires in Grand Canyon National Park, authorities said at that time.

Mayor grateful

San Jose Mayor Chuck Reed applauded the firefighters and police officers who tracked down the suspect.

"I'd also like to thank the dedicated residents who came together to keep watch over their neighborhoods and help our officers and firefighters solve these horrible crimes," Reed said. "The collaboration between our residents and public safety departments is one of the things that help make San Jose a great place to live, work and raise a family."