Sometimes Paul Miller dressed as Batman’s nemesis, the Joker — face paint and all. Other times he wore army-green tactical gear with a red armband adorned with a swastika. But in each video, Miller toggled between chats on Omegle, a website that randomly pairs users, waving a gun and making hateful statements.

“Do you think we should gas the Jews?” he asked a group of young teenage boys.

“Ship them all back to Africa … make them slaves again,” he said to another man, referring to Black people as the n-word.

“White power,” he said emphatically, raising his right arm in the Nazi salute.

Miller, a 32-year-old who went by “GypsyCrusader” online, was open about his extremist beliefs in videos reviewed by The Washington Post that remain active on BitChute, a posting site popular with the far right. In March, the FBI Joint Terrorism Task Force took his threats seriously. During a raid of his Fort Lauderdale, Fla., home, investigators discovered a rifle and almost 850 rounds of ammunition.

On Tuesday, Miller pleaded guilty to three felony counts for possession of an unregistered firearm and ammunition and possession of a weapon as a felon. He faces a maximum of 30 years in federal prison.

Miller’s lawyer had no comment.

The case follows the FBI’s emphasis on combating domestic terrorism following the January insurrection as officials warn that far-right extremism poses the greatest threat of violence. Last week, President Biden announced an ambitious strategy to combat the problem by coordinating efforts across agencies and increasing budgets for the FBI and Justice Department to hire more analysts, prosecutors and investigators.

Domestic terrorism data shows right-wing violence is on the rise in America. Here's how lawmakers and the FBI are responding. (Sarah Hashemi, Monica Rodman, Monica Akhtar/The Washington Post)

Miller, a New Jersey native, was already a felon when he was charged in March. In 2007, he pleaded guilty to aggravated assault and drug possession with the intent to distribute. Miller told investigators in March that he was convicted of firing a pellet gun out of a window and hitting people, according to the recent criminal complaint. He was also under indictment for possession of a firearm by a felon from a 2018 incident, though court documents did not elaborate on the details of the charge.

When the FBI raided Miller’s Fort Lauderdale home the morning of March 2, authorities found 848 rounds of ammunition for three different caliber weapons, according to court documents. They also found parts to an unregistered firearm.

“Inside a dryer in Miller’s residence, authorities also discovered a lower receiver for a rifle, attached to a collapsible rifle stock, and disassembled from an upper receiver featuring a 10.5 inch barrel,” the criminal complaint said. “None of these parts bore any manufacturer markings or serial numbers.”

The lead federal agent on the case noted in court documents that Miller obtained ammunition across state lines since “there are no models of ammunition manufactured within Florida.”

During an interview with law enforcement following his arrest, Miller said he bought $500 worth of ammunition and rifle parts from a gun show shortly after he and his family received threats from “antifa” and “Black Lives Matter,” according to court documents. He said he watched YouTube tutorials on how to assemble the rifle.

Miller then defended his possession of the firearm, claiming he thought his actions were legal.

“I’m scared, I’m living alone, I don’t have anybody with me,” he told investigators, according to the affidavit. “Somebody’s going to, these people are trying to kill me.”

He went on to justify his decision to build a gun rather than purchase one because “he believed America was on the brink of collapse and that firearm manufacturing would be a ‘good skill to learn’ as a result,” court documents said.

Miller has been cited by watchdog groups as an extremist using social media to spread racist, antisemitic and homophobic ideology. Last November, the Anti-Defamation League mentioned him in a blog post about “extremist trolls” on Omegle, labeling him a “Florida-based white supremacist.”

The ADL noted that Miller live-streamed on various platforms before uploading his videos to BitChute, where more than 3,000 people subscribed to his channel by November.

He also had a loyal following on Telegram, where he described himself as an “investigative journalist” with “News for Patriots Christians and God loving Americans,” according to the Miami Herald. Miller racked up more than 40,000 followers on the messaging app by the time of his arrest in March, the South Florida Sun-Sentinel reported.

In videos of his live streams reviewed by The Post, Miller repeatedly says the n-word and makes other racist comments. He also spread antisemitic stereotypes, and called for Jewish and Black people to be “hung.” He also spewed homophobic and anti-Asian slurs. On several occasions, he made racist remarks about Latinos and sexist comments to underage women.

Prosecutors noted Miller was preparing for “a coming civil war,” the Sun-Sentinel reported, and added while he hadn’t acted on his threats, he was “on the precipice.”

At the time of his arrest, the ADL said on Twitter that it had followed his activities for five months leading up to his arrest and had shared “significant intelligence” with federal investigators.

Some of Miller’s supporters joined his hearing over Zoom on Tuesday, according to the Sun-Sentinel. Many made racist and antisemitic comments in the chat and at one point, Miller grew visibly uncomfortable when he saw someone he recognized from the Internet on the screen.

Miller apologized to his attorney, Michael B. Cohen, according to the Sun-Sentinel.

“I’m sorry Mr. Cohen. I never wanted anything like this,” he said.

“I just don’t want them to blame me for it,” he added, referring to the prosecutors and the judge.

Miller is due to be sentenced on Aug. 30, the Sun-Sentinel reported.