Florida white supremacist arrested for threatening shooting at Walmart, police say Richard Clayton, 26, made the threats online, Florida authorities said.

A Florida white supremacist has been arrested for threatening a shooting at a Walmart just days after 22 people were killed at a Walmart in El Paso, Texas, in one of the worst mass shootings in the country's modern history.

Richard Clayton, 26, was arrested by Florida Department of Law Enforcement authorities on Friday in Winter Park after making an online threat last week, according to police.

On Aug. 6, Clayton allegedly posted on Facebook, "3 more days of probation left then I get my AR-15 back. Don’t go to Walmart next week."

The threat echoes the shooting allegedly carried out by Patrick Crusius in El Paso on Aug. 3. The suspect entered the Walmart and opened fire with an AR-15 assault rifle. Nearly 50 people were hit by the gunfire before the suspect exited the store and was later arrested a short distance away.

Police said Crusius, a native of Allen, Texas, some 10 hours away, admitted to the crime and said he was trying to kill as many Mexicans as he could. He also posted a "manifesto" online espousing white supremacist and anti-immigrant sentiments.

Florida authorities said Clayton holds some of the same beliefs.

"Clayton appears to believe in the white supremacist ideology and has a history of posting threats on Facebook using fictitious accounts," Florida Department of Law Enforcement officials said.

He was not on probation, despite his threat, Florida officials told The Associated Press.

Clayton was charged with intimidation through a written threat and is being held at Orange County Jail on $15,000 bond.

The arrest was among a number of recent cases of police departments nationwide targeting white supremacist threats.

Conor Climo, a 23-year-old from Las Vegas, was arrested on Thursday for allegedly possessing bomb-making materials and espousing neo-Nazi and white supremacist ideology with an undercover FBI agent online. He was allegedly planning on fire-bombing a synagogue in Las Vegas and hoped to stage a mass shooting at a gay nightclub as well.

A "significant portion," about one-third, of all domestic terrorism cases involve white supremacist ideology, according to the FBI. Director Christopher Wray testified about the issue in a lengthy hearing before the Senate Judiciary Committee on July 23, but said the bureau's "focus is on the violence."

"We don't investigate ideology, no matter how repugnant," Wray said.

ABC News' Gina Sunseri and Mike Levine contributed to this report.