His Facebook pages are littered with photos of him brandishing guns and knives with captions such as “coming to a synagogue near you.” He routinely shared disturbing right-wing memes, including one depicting a bleeding woman hanged for dating outside her race.

And when others online challenged Fred C. Arena, an avowed white supremacist and internet troll, he boasted of doxxing and haranguing a former ally until the man “was ready to kill himself.”

But the question before a federal court Wednesday — nearly two weeks after the former Navy Yard worker was charged with lying to the FBI about his ties to white nationalist groups — was whether that long record of racist vitriol and online harassment made him an actual safety risk, or meant he was just another blowhard with an internet connection and extremist views.

U.S. Magistrate Judge David R. Strawbridge chose the former and ordered Arena detained without bail until trial. He credited prosecutors’ depiction of the 41-year-old Salem, N.J., resident as a danger to the community and potential witnesses in his case.

"I believe on these facts that there is enough,” he said.

Strawbridge’s decision came after a series of hearings over the last week in which Arena’s attorney, Brian J. Zeiger, accused government lawyers of seeking to jail his client solely for distasteful beliefs.

He challenged the assertion that Arena’s racist Facebook posts and photos with guns were proof that he posed an imminent danger, and argued that the crime he is charged with — lying to federal agents — was not serious enough to warrant pretrial detention.

A photo from one of Fred C. Arena's Facebook pages showing him holding an AR-15 style rifle next to a comment that reads "Coming to a synagogue near you." Prosecutors charged Arena Oct. 25 with lying about his ties to white nationalist groups.
Facebook photo taken from court filings
A photo from one of Fred C. Arena's Facebook pages showing him holding an AR-15 style rifle next to a comment that reads "Coming to a synagogue near you." Prosecutors charged Arena Oct. 25 with lying about his ties to white nationalist groups.

“Every single thing in those photos is legal under the First and Second Amendments,” Zeiger said during proceedings Thursday. “It’s not illegal to be a member of one of those groups.”

Arena, who had never before been charged with a crime, is accused of repeatedly lying about his membership in the white nationalist group Vanguard America.

The organization marched in the 2017 “Unite the Right” rally in Charlottesville, Va., which sparked violent clashes between white nationalists and counterprotesters that left one woman dead.

Arena’s name surfaced as a Vanguard member nearly a year later, when the alternative media site Unicorn Riot unmasked him based on pseudonymous postings to white supremacist chat groups. FBI agents interviewed Arena days later, but he allegedly denied any association with the group.

Prosecutors say this photo taken from one of Fred C. Arena's social media accounts depicts him at the 2017 "Unite the Right" rally in Charlottesville, Va., where clashes between white supremacists and counterprotesters left one woman dead.
Facebook photo taken from court filings
Prosecutors say this photo taken from one of Fred C. Arena's social media accounts depicts him at the 2017 "Unite the Right" rally in Charlottesville, Va., where clashes between white supremacists and counterprotesters left one woman dead.

Prosecutors also say Arena lied on an application for national security clearance that he submitted in January as part of his job as a government contractor at the Naval Inactive Ship Maintenance Facility, the area of the Navy Yard where the military houses out-of-work ships.

Arena has denied the allegations, and has spent most of his time in court smirking, laughing, and mouthing “no” as prosecutors have laid out their case. But the issue of his guilt in his criminal case is distinct from whether he is too dangerous to be granted bail.

“Generally speaking, you have a right to bail,” Zeiger said during Wednesday’s proceedings. “We’re in a stance here where the government is saying this person doesn’t have that right. When I look back at the sort of cases where that’s the case, this doesn’t even compare.”

There are no allegations of violence in Arena’s underlying charges, and federal guidelines suggest a prison sentence of less than a year if he’s convicted, though prosecutors have said they are likely to ask the court to exceed that.

The U.S. Supreme Court has repeatedly protected hateful or inflammatory speech, saying it crosses the line into illegality only when it is likely to provoke violence.

But in an age where mass shooters routinely post hate-filled manifestos online before their attacks, the line between what is offensive and what is a harbinger of specific danger has become hazier.

A photo taken from Fred Arena's Facebook page in which he is depicted brandishing a knife and threatening Muslims. Arena, a Navy Yard employee, is charged with lying to federal agents about his ties to white supremacist groups.
Facebook photo taken from court filings
A photo taken from Fred Arena's Facebook page in which he is depicted brandishing a knife and threatening Muslims. Arena, a Navy Yard employee, is charged with lying to federal agents about his ties to white supremacist groups.

“This is obviously an atypical case,” Strawbridge said after reviewing Arena’s social media postings on Oct. 31. “Those images, I think we would all agree, are offensive. It’s offensive to me. But offensive is one thing, acting out is another.”

The judge after last week’s hearing had ordered prosecutors to return to court with evidence that Arena posed a specific danger to government witnesses or others.

Assistant U.S. Attorney Joseph A. LaBar showed up Wednesday with plenty — including alleged social media posts that detail Arena’s apparent obsession with anyone he believed to be feeding information about him to the FBI.

“One day they are going to feel my wrath,” Arena said in one January post cited by prosecutors in which he concluded a former ally was cooperating with law enforcement.

He boasted of posting the man’s number on Facebook and inviting others to harass him. And later, Arena told an online associate he drove to the suspected informant’s home outside Charlottesville and took a selfie of himself next to the town sign while holding a knife.

“We drove [him] so crazy, he was ready to kill himself,” Arena wrote.

Prosecutors also say Arena made online and verbal threats to former romantic partners, two of whom the FBI has questioned.

“He threatened to sever intimate parts of the women’s bodies and store the parts in a jar,” LaBar wrote. He allegedly told another woman he would “eat [her] alive” and cut her throat — remarks Arena says were made in jest.

“How do we decide what an individual’s intentions are?” LaBar asked Wednesday. “We look to his past actions and his past statements. And I think these statements show an intent to intimidate witnesses.”

Arena has remained in the federal detention center in Philadelphia since FBI agents arrested him in a hotel room he was renting as temporary housing. Strawbridge, in his decision Wednesday, cited the fact that Arena has no fixed address. His family refused to allow him to live with them had he been released and he was fired from his job at the Navy Yard last week.

No trial date has been set in his case.