SAN FRANCISCO (CBS SF) — A former U.S. Marine from Northern California has been arrested for allegedly offering to carry out a terrorist attack on Christmas Day in San Francisco at the Pier 39 tourist attraction.

FBI agents arrested 26-year-old Everitt Aaron Jameson in Modesto on Friday morning, according to the U.S. Department of Justice. He is charged with attempting to provide material support to a foreign terrorist organization.

Jameson appeared in a federal court in Fresno Friday afternoon. His public defender, Eric Kersten, denied the allegations but did not enter a plea. Jameson was described as stoic and mostly silent during Friday’s proceedings, only occasionally speaking privately with Kersten.

According to the criminal complaint unsealed Friday, Jameson “has espoused radical jihadi beliefs, including authoring social media posts that are supportive of terrorism, communicating with people he believes share his jihadi views and offering to provide services to such people …”

Jameson allegedly detailed his plans for the terror attack with an undercover FBI agent whom he believed was associated with the senior leadership of ISIS. The alleged plot involved setting off explosives remotely in one area of Pier 39 and then mowing people down with automatic rifle fire as they fled.

From the FBI complaint:

Jameson specifically named Pier 39 in San Francisco as a target location because he had been there before and knew that it was a heavily crowded area, and that, according to Jameson, no reconnaissance or site survey would be necessary (because Jameson already was familiar with the area). Jameson explained that he also desired to use explosives, and described a plan in which explosives could “tunnel” or “funnel” people into a location where Jameson could inflict casualties.

The complaint said Jameson suggested to the undercover agent that Christmas Day would be a “perfect day” for an attack. Jameson also told the agent “he did not have and did not need an escape plan because he was ready to die.”

The plot seemed to unravel earlier this week. Jameson told the agent that he had second thoughts about carrying out his plan, but agents had enough evidence to search his Modesto home, according to the complaint.

Rifles, a handgun and ammunition were also found during the search of his home.

During the search, FBI agents interviewed Jameson, who observed,

At periodic times during that interview Jameson state his support of ISIS and terrorism and discussed aspects of the plan to carry out an attack, noting that he would be happy if an attack was carried out.

Agents said a suicide note written by Jameson was also found at the home, which took credit for what was to be the Pier 39 attack. The note read, “You all have brought this upon yourselves,” and denounced this week’s announcement by President Donald Trump that the U.S. would recognize Jerusalem as Israel’s capital.

Jameson graduated from basic recruit training in the U.S. Marine Corps in 2009 and earning the “sharpshooter” rifle qualification. He was later discharged for “fraudulent enlistment” after he failed to disclose a latent asthma history, according to the complaint.

Jameson is a Modesto resident who recently took a job as a tow truck driver. The Islamic Center of Merced told KPIX he attended their facility and was a recent convert to Islam.

San Francisco acting mayor London Breed in a statement said while there were no known additional threats related to the investigation, the police department would be increasing its presence in the city as the FBI investigation continued.

“I am incredibly thankful for the efforts and commitment of our public safety officials during this time,” said Breed. “San Francisco is a city that proudly champions democracy, freedom and liberty. Sadly, that makes our home a target. We will not allow the thwarted attempts of one dangerous individual to disrupt our way of life. We will remain vigilant and continue to protect our city from any threat.”

Attorney General Jeff Sessions thanked the FBI agents and prosecutors involved in the case. “Today, our incredible law enforcement officers have once again helped thwart an alleged plot to kill Americans,” Sessions said.

If convicted, he faces a maximum 20 years in prison and a $250,000 fine.