FRESNO (CBS SF/AP) — A Central Valley man arrested in a plot to stage a Christmas Day bombing and shooting attack at San Francisco’s Pier 39 pleaded guilty Monday to attempting to provide support to ISIS in a plea deal with federal prosecutors.

Everitt Aaron Jameson now faces 15 years in federal prison when he is sentenced on Sept. 4.

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As part of the plea deal, prosecutors dropped a second charge of distributing bomb-making information.

The 26-year-old ex-U.S. Marine was working as a tow truck driver in the Modesto area when he allegedly spoke to an FBI informant whom he believed was an ISIS leader.

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He told the undercover agents how to build pipe bombs and where he intended to assemble the bombs, and he asked them for remote timers, according to court documents.

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Each charge carries a maximum penalty of 20 years in prison, and Jameson didn’t want to take the chance of receiving a 40-year sentence, defense attorney Charles Lee said.

Lee said his client was having second thoughts and didn’t actually take steps to carry out the plot. Lee said investigators found no bomb-making materials, and three firearms found during a search were legally owned by his stepfather and were locked in a gun case where Jameson couldn’t to get them.

An undercover agent told Jameson several times to think about what he was doing, according to the FBI, and each time Jameson said he was ready to attack. Agents also recovered a martyr’s letter signed with an Islamic variation of Jameson’s name.

Jameson was discharged from the Marines for having an allergic reaction to a bee sting, had a “tumultuous marriage” in which his wife went to prison for attacking him with a knife, and he lost parental rights to his two children two days before he first talked to agents, Lee said.

“Every time the government’s been involved in his life, it’s turned out poorly for him,” Lee said. “I do believe he was very susceptible to suggestion.”

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