In 2017, Antifa, a loose collection of left-leaning militant anti-fascist groups, was blamed by many for a series of violent threats mailed to a Virginia organization that hosts Civil War reenactments, as well as a pipe bomb planted at one of its annual gatherings.

Now the FBI believes those threats likely didn’t come from Antifa at all, but instead from a member of the Civil War reenactment group itself.

A search warrant application seeking phone records for Gerald Leonard Drake, a former volunteer at the nonprofit Cedar Creek Battlefield Foundation in Middletown, Virginia, was unsealed today in federal court. The filing lays out evidence that Drake, a 61-year-old registered sex offender who has spent time in prison, sent the letters to exact revenge on Cedar Creek after it kicked him out of his unit. The document does not say which side Drake fought for during the reenactments, but email addresses for Drake listed in public records include variations on the word “confederate.”

Drake, it appears, attempted to leverage existing tensions between Antifa and the far-right. Members of Antifa will often show up at rallies held by far-right white supremacist groups and organizations defending so-called “Confederate heritage.” Skirmishes between the two sides sometimes break out at these competing demonstrations.

The Cedar Creek Battlefield Foundation every year reenacts the Battle of Cedar Creek, an 1864 fight that began with a sneak attack by Confederate troops, but ended with a Union victory. The mailed threats, and a pipe bomb found at Cedar Creek’s 2017 reenactment, prompted the foundation to cancel the annual event in 2018.

Reactions from the right were vitriolic. Right-wing media outlets and message board postings blamed the situation on, variously, “lib terrorists,” “attention-seeking organizations and anarchists,” and “leftists.”

“If Civil War reenactments are somehow unacceptable because of people playing the roles of Confederate soldiers, how much further must this effort to erase history go?” asked an article in the National Review. “Museums? Books? Movies or television shows?

“Its [sic] only a matter of time before the general population signals that its [sic] had enough and starts turning the tables on these violent fascist antifa fcks [sic],” said one commenter in an online firearms forum.

“You know this was coming, the left can’t get over their stunning loss,” said another, apparently referring to US president Donald Trump’s 2016 election victory. “Anything that reminds them of their failures must be attacked a racist [sic].”

The first threat sent to the group was postmarked Sept. 21, 2017 and included an Antifa symbol printed on the outside of the envelope. It was addressed to “Cedar Creek Battlefield Event People.”

The letter read, in part:

“You need to cancel your coming up celebration of the Civil War on October 13, 14, 15, 2017…Many of us have dogs, so will bring dog feces to throw on people! We will also throw cups of human urine! We might resort to actually firing guns into the camps and at the re-enactors! We will put poison in the water, we will use noise to disrupt the battles and sleep! These events must stop! Our local organizer tells us he is ready to go! You have been warned, now if it is not called off, we will destroy you! You have less than 1 month to issue a cancellation notice, do it asap!”

Despite the threat, the reenactment went ahead as planned. On its second day, an unexploded pipe bomb was discovered on the grounds. No one claimed responsibility.

Another letter was sent the following summer, this time addressed to Joe D’Arezzo, the Cedar Creek Battlefield Foundation’s president. The threat again included an Antifa symbol. The sender threatened to kill D’Arezzo’s mother with a car bomb if he didn’t cancel the 2018 reenactment.

“Don’t think metal detectors will help, we have plastic pipe bombs,” a portion of the threat said. “If you won’t stop this celebration of slavery than maybe we need to hurt the participants to stop it instead of just the visitors…We are the ones that did it to you last year, we used a bad bomb guy his mercury switch, and rocket launch wire didn’t work on the pipe bomb covered in nuts, just so you know we are real and returning.”

The foundation decided to call off the 2018 event. D’Arezzo then resigned because, he said, the organization wasn’t taking security seriously enough. His replacement, Jeannette Shaffer, then received another threat that read, in part: “If Jeannette Shaffer thinks she is safe, well she is right, but her children are not!”

As the FBI investigated the threats, certain details raised red flags. According to an FBI affidavit attached to the search warrant application, the Cedar Creek Battlefield Foundation is a small organization with just one full-time employee, 12 board members, and a “small number” of volunteers. The person sending the threats somehow knew a lot about the inner workings of the group, including specific operating procedures, plans, and names only an insider would know. The sender was also strangely fixated with a former Cedar Creek volunteer named Shawn Mowbray, who hadn’t worked there since 2014.

“You also have a rat in your place, our information about everything you are or were doing came from him,” one of the letters said. “Yes, we like real information, but we also hate rats. You might want to get rid of him. Shawn Mowbray is your rat. We will continue to get information from our other friends.”

Investigators eventually learned that the group had removed Drake from his reenactment unit after a disagreement he had with Mowbray, who was a member of the same unit. Surveillance footage reviewed by the FBI placed Drake’s car at the scene where the pipe bomb was discovered in 2017. Law enforcement also obtained eight pages of diagrams Drake had drawn while in prison a decade earlier. They included detailed sketches of pipe bombs, a grenade, a propane bomb, a Coleman fuel bomb, and a CO2 cartridge bomb.

“The pipe bomb diagrams were similar to the pipe bomb discovered at the Cedar Creek Battle reenactment in 2017,” the FBI affidavit says.

The FBI also linked Drake to messages on Reddit that investigators said indicated a “negative attitude toward the [Cedar Creek] event, possibly due to the incident with Mowbray in 2014.” Other postings used language similar to that found in the mailed threats.

Drake was unable to be reached for comment. He does not have a lawyer listed in court filings.