An 18-year-old man who allegedly fantasized on a popular message board about killing civilians and federal agents told the FBI the posts were “only a joke” when they arrested him last week, according to court documents unsealed Monday.

Law enforcement found more than two dozen guns and 10,000 rounds of ammunition in the home he was sharing with his father, according to the criminal complaint against him.

For months, Justin Olsen posted text-dense screeds and memes under the username “ArmyofChrist” to his thousands of followers on the website iFunny.co, the popular image-based message board.

He was arrested Wednesday at his home near Youngstown, Ohio and charged with threatening to assault a federal law enforcement officer.

After a search of Olsen’s father’s Boardman, Ohio house, where Olsen was living, investigators allegedly found “rifle cases, approximately 10,000 rounds of ammunition, camouflage clothing, and camouflaged backpacks,” as well as a gun vault. The gun cases and ammo were found throughout the house.

The gun vault contained “several firearms to include AR-15 style rifles and shotguns,” according to an FBI special agent’s affidavit included in the complaint.

According to the affidavit, Olsen first came under FBI scrutiny on Feb. 11, after he posted on iFunny about mass shootings and targeting Planned Parenthood.

According to TPM review of the “ArmyofChrist” iFunny page, which was still live on Tuesday, a post from that day includes a GIF showing a man indiscriminately shooting guns below the caption, “Me walking into the nearest Planned Parenthood.”

A few days later, another post still visible Tuesday read: “Bombing Planned Parenthood is noble, as is the killing of abortionists. Women who get abortions should receive the death penalty.”

After noting a “large increase in subscribers” in March — 4,400 people were subscribed to“ArmyofChrist”’s posts at the time, the affidavit said — the FBI issued a subpoena to the website for ArmyofChrist’s subscriber information, and subsequently to Google for information associated with the email account Olsen used to make his iFunny account, according to the affidavit.

In June, Olsen made the post that, per the affidavit, prompted to the federal charge against him.

During a discussion of the siege of the Branch Davidians compound in Waco, Texas in 1993, which left dozens of people dead and has since become a cornerstone of extremist anti-government rhetoric, Olsen wrote, “In conclusion, shoot every federal agent on sight.”

The affidavit noted another post Olsen made, in which he claimed the Oklahoma City federal building bombing “shows that armed resistance is a viable method of political change.”

After his arrest, Olsen allegedly admitted to making the posts but told law enforcement they were “only a joke,” the FBI agent said in his affidavit.

“That’s a hyperbolic conclusion based on the results of the Waco siege,” he said, per the affidavit, adding: “where the ATF slaughtered families.”

Dozens of posts still visible on Olsen’s account Tuesday include signs of potentially violent far-right extremism.

One post from June includes a photo of soldiers below the caption, “Repub if you would make an ethnostate in Montana with your male followers.” Others refer to Jews’ “constant Holocaust worship” and an “invasion” of undocumented immigrants into the United States.

Yet another post referred to the Boogaloo, a meme that repurposes the title of the mediocre sequel to an 80’s breakdancing movie into a reference to the second civil war.

“Boogaloo better be in my lifetime or I’m just gonna be wasting a lot of money on guns and ammo in the next twenty years,” Olsen wrote.

In January, Olsen bragged on iFunny about being offered a 4-year ROTC scholarship to the University of Texas at Austin, the University of Alabama and Ohio State University.

A spokesperson for the University of Alabama told TPM in an email that Olsen is not enrolled as a current or incoming student. The University of Texas at Austin said that while federal law prevented the school “from discussing details regarding any specific student,” the university had procedures in place for rescinding admissions in certain cases.

H/t WKBN.