Rickie Lee Fowler, 30, of San Bernardino is accused of igniting the deadly blaze that burned more than 91,000 acres and destroyed more than 1,000 structures.
But in February 2004, he told law enforcement officers and a polygrapher that he was not the firestarter.
"Would you be willing to take a polygraph?" Sgt. Joe Palomino, who at that time was a detective with the San Bernardino County Sheriff's Department, asked Fowler during a recorded interview.
"Yeah, I want to," Fowler said. "It'll clear up my name."
Fowler has been charged with five counts of murder and special circumstances, which allow prosecutors to pursue the death penalty if he is convicted. Prosecutors say five residents in burn areas died from heart attacks that were caused by the stress of evacuation and threats to homes and belongings.
Defense attorney Donald Jordan played two audio recordings Tuesday during the Fowler trial.
In the interview with Palomino, Fowler said a friend of his joked about starting the Old Fire as they watched news coverage of the burning homes.
"He would say, `Well, I could've did it, I could've walked up there and did it,"' Fowler said. "And we were like, `Dude, don't say (stuff) like that. Don't even play like that. It could come back on you."'
Later, Palomino asked Fowler if he had anything to do with the fire in Old Waterman Canyon.
"Hell no," Fowler said.
Palomino suggested the polygraph test and Fowler was more than willing to participate.
Robert Heard, who conducted the polygraph test in February 2004, explained the process of the test and asked Fowler a series of questions.
Every time Heard asked Fowler if he was involved in setting the fire in Waterman Canyon, Fowler said no. Then, Heard changed the wording of his question and asked Fowler several times if he was present at the time of the fire.
Every time Fowler said no.
Jordan is expected to play the remainder of the recording - which will include the results of the polygraph - today.
On Tuesday, Superior Court Judge Michael A. Smith told the jury that polygraphs are generally not admitted into trials because they are considered unreliable.
"Don't accept that as being true and don't accept that as evidence," Smith said before the audio started playing. "Only consider that as the context in which the person is speaking."
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