FBI disrupts plot targeting UFC event: Sources

Five people are in custody, according to court documents.

The FBI disrupted an alleged plot targeting the "UFC Freedom 250" fights at the White House on Sunday that included explosive drones designed to target buildings in the area to spark a mass evacuation, according to authorities.

Five people are in custody as of Tuesday morning, authorities said, and one person has been formally charged. The suspects were allegedly in Signal chats discussing preoperational plans, according to court documents, with some of those involved in the plot allegedly traveling to Fredericksburg, Virginia, on June 12 or 13.

FBI and Department of Homeland Security officials warned in a bulletin earlier this month that the fights were "attractive symbolic targets." There were no credible threats listed in the bulletin at the time.

The Ultimate Fighting Championship event was held in the evening on Sunday, June 14, on the grounds of the White House. Billed as a celebration of America's 250th anniversary, it also coincided with the 80th birthday of President Donald Trump, who was in attendance.

The alleged plot involved explosive-laden drones, according to court documents, which were designed to hit buildings in the area to spur a mass evacuation.

A "second wave" targeting a security checkpoint was then planned, authorities said.

In a statement to ABC News, FBI Director Kash Patel praised the "rapid action" of the FBI and its partners, that involved a "a multi-state operation."

Federal prosecutors unsealed a criminal complaint on Tuesday charging 19-year-old Tycen Proper, of Ohio, with conspiring against the United States, attempted murder of an officer of the U.S. and firearms charges in connection with the alleged weekend plot.

Officers with the Knox County Sheriff's Office and Danville Police Department were dispatched to Proper's home on June 10 after his mother raised concerns about his recent actions including firearms purchases and communications with certain individuals online, according to the complaint.

When officers spoke to his parents, they said Proper had recently met people online and had been planning "recons" with them. They also said he had plans to leave to meet up with them the weekend of June 13, according to the complaint.

Proper's father told investigators the 19-year-old had recently acquired camping gear, food, ballistic plates, a new shotgun and rifle and "lots" of ammunition, using roughly $3,000 of money he had received for graduation, the complaint alleges.

Proper's mother told investigators he "had recently begun interacting with a group online that was comprised of individuals who claimed to be ex-military and Christian-based" who had "expressed ultra-religious and antigovernment sentiments, specifically citing grievances about government corruption, the handling of the Epstein files, data centers taking up all the water in communities, and other government actions," according to prosecutors.

The suspect's mother also told investigators she had observed him engaging in physical training and that she had overheard recent conversations her son had allegedly been having with this online group, the complaint said.

Proper allegedly told his mother he couldn't tell her exactly what they were planning but described "recon" and "hit and run" missions which she believed meant conducting shootings and leaving, according to the complaint.

Prosecutors said Proper also allegedly quit his job recently in preparation to meet the individuals he was interacting with online.

During an interview on June 11 at the medical facility, Proper allegedly admitted to planning a coordinated attack at the UFC event held at the White House, according to prosecutors.

Proper told investigators that members of the group he was communicating with "believed that the United States needed to be torn down so that it could be rebuilt" and that their coordinated attack would help bring about a revolution, according to the complaint.

He told investigators he was allegedly planning to drive to Fredericksburg, Virginia, to meet up with other members of the group -- taking his weapons, body armor and ammunition including an AR-15, according to the complaint.

"PROPER said that although he was not going to the protest in order to shoot people, several other members of the group were intent on violence," the complaint alleged.

The complaint alleged that a review of Proper's cellphone revealed Signal chats aligning with the alleged plotting and members specifically discussed escape and evasion resources for the attack, a location of a potential "safe house" and other plans -- one of which included members of the group planning to travel from the White House to the Potomac River to escape.

In one of the chats, Proper allegedly identified Sen. Marsha Blackburn as a target for her support for Israel and then sent other images of politicians including Sen. Jim Justice, Sen. Shelly Moore Capito, Rep. Carol Miller and Rep. Riley Moore, according to the complaint.

Proper was transported to the local hospital after the interview where they submitted an application for admission based on "homicidal ideations," the complaint said.

Proper has not entered a plea yet, according to court records. An attorney for Proper did not immediately respond to ABC News' request for comment.

Patel said the law enforcement response included a "multi-state operation."

"While the result represented the best of investigative work, it was also nothing out of the ordinary for this law enforcement team -- we are built to detect, respond to, and bring to justice those who threaten the lives of American citizens -- particularly during large gatherings like the historic UFC 250 fight," Patel said in his statement. "That’s exactly what we did here. I want to thank our great agents and partners, this work remains ongoing and we will continue to update the public as permitted."

Federal law prohibits flying drones in the airspace over the National Capital Region, the special agent in charge of the Secret Service’s Washington field office told ABC News last week.

"We will have law enforcement drones for overwatch, but just to make it simple for the public, if they see a drone, we want them to report that," Tara McLeese, the special agent in charge, said at the time.

-ABC News' Josh Margolin contributed to this report.

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