A 20-year Marine veteran and former marksmanship instructor from Florida became the second defendant in the largest Jan. 6 Oath Keepers conspiracy case to plead guilty and agree to cooperate fully with prosecutors in hopes of reducing his prison term.

Jason Dolan, 45, of Wellington, Fla., admitted Wednesday to two federal counts of conspiracy and aiding and abetting the obstruction of Congress as it met to confirm President Biden’s 2020 election win, felonies punishable by up to 20 years in prison.

In a plea deal with prosecutors, both sides agreed that Dolan, who has no prior convictions, could face 63 to 78 months under advisory federal sentencing guidelines. However, the government agreed to request a lower term at sentencing in exchange for his “substantial assistance.”

Dolan, a former security guard at the Four Seasons resort in Palm Beach, was the second of 18 alleged associates of the extremist anti-government group charged in a single indictment in the assault on the U.S. Capitol to plead guilty, following Graydon Young, 55, of Englewood, Fla.

In plea papers, Dolan admitted being among a group that forced entry through the Capitol’s East Rotunda doors after marching single file in a stack up the steps wearing camouflage vests, helmets, goggles and Oath Keepers insignia. He acknowledged bringing a rifle to Washington with others in the group who were stashing weapons beforehand at a Ballston hotel in case a “Quick Reaction Force” was needed.

Dolan was charged on May 27 with five counts, including rioting and destruction of federal property. Prosecutors agreed under the deal to dismiss the three other charges.

Prosecutors alleged the Oath Keepers group came to Washington at the urging of founder Stewart Rhodes, usually identified as “Person One” by the government in court documents. In court filings, prosecutors have asserted that Rhodes began discussing plans to keep President Donald Trump in the White House by force as early as Nov. 9 and exchanged dozens of encrypted messages, phone calls and other communications with members of the “stack” group before and during the riot.

Rhodes, 56, has not been charged and is not accused of wrongdoing. He has accused prosecutors of trying to manufacture a nonexistent conspiracy.

“I may go to jail soon, not for anything I actually did but for made-up crimes,” Rhodes told Texas Republicans at a March rally in Laredo. He urged Trump supporters to “not cower in fear” and claimed that the federal government “was trying to get rid of us so they can get to you.”

Last week, Kellye SoRelle, a lawyer for the Oath Keepers who was with Rhodes outside the Capitol on Jan. 6, said the FBI seized an iPhone from her. A related search warrant stated that investigators are continuing to probe whether Rhodes’s associates conspired to subvert the election results or violate seditious conspiracy laws, as first reported by Mother Jones.

Dolan attorneys Michael van der Veen — who represented Trump in his second impeachment trial — and Libbey Van Pelt did not respond to a request for comment.

In an interview with the right-wing Gateway Pundit website arranged with the help of SoRelle that prosecutors attributed to Dolan, the former Marine before his arrest initially suggested that Capitol officials intentionally opened the doors, adding, “As far as I know there was never any preplanned intention, operation, criteria, to go into the Capitol.”

However, Dolan said otherwise in a signed plea statement. At the time he unlawfully entered the building, Dolan “believed that he and the co-conspirators were trying to obstruct, influence, and impede” Congress, intended to disrupt it, and did so by “intimidating and coercing governmental personnel.”

Inside the Capitol, Dolan repeatedly chanted “Treason!” in reference to lawmakers, and later obstructed the investigation by deleting from his cellphone data, including photographs from inside the Capitol and encrypted communications, Dolan admitted in his plea.

Federal prosecutors have charged roughly 22 members and alleged Oath Keepers associates overall, including four others who have pleaded guilty and agreed to help investigators.

Only Young and Dolan were charged as part of the main conspiracy case, however.

Both men agreed to testify before a grand jury, to speak with investigators as requested, and to turn over financial information.

At a brief court hearing, U.S. District Judge Amit P. Mehta in Washington accepted Dolan’s plea, left him on conditional release, and gave prosecutors until Dec. 17 to provide an update on the investigation and whether the case is ready for sentencing.

“Has anyone forced or coerced you to plead guilty?” Mehta asked.

“No, sir,” Dolan replied.

“Then how do you plead . . . ?”

“Guilty,” Dolan said.