Accused gunman Cole Tomas Allen allegedly opened fire during an attempted assassination of President Donald Trump at the White House Correspondents’ Dinner, Breaking Celebrity News can reveal.

According to federal prosecutors, the horrific shooting on Saturday, April 25, was "premeditated, violent, and calculated to cause death."

According to newly filed federal court documents exclusively obtained by Radar, the chaos unfolded shortly after 8:30 p.m. when Allen approached a Secret Service security checkpoint inside the Washington Hilton, where Trump, the First Lady, Vice President JD Vance, and top Cabinet officials were gathered.

Prosecutors allege Allen discarded a coat concealing a 12-gauge shotgun before sprinting through a magnetometer and charging toward a staircase leading directly to the ballroom.

A Secret Service officer allegedly observed Allen raise the weapon and fire toward the stairs – triggering immediate panic.

The agent returned fire, discharging multiple rounds and stopping the suspect before he could reach the crowded event space.

Authorities have insisted the outcome could have been catastrophic if he hadn't been stopped.

Feds described the alleged attack as a calculated act of political violence that risked the lives of hundreds, noting Allen was armed with a shotgun, a loaded .38 caliber pistol, knives, daggers, and additional ammunition at the time of his arrest.

But the chilling plot didn’t begin that night.

Investigators claim Allen's alleged plan unfolded over several weeks, beginning in early March after the President publicly confirmed he would attend the annual dinner.

By April 6, Allen allegedly had already begun researching the event online, according to prosecutors, before securing a hotel reservation at the Washington Hilton, the same venue hosting the high-profile gathering.

In the days that followed, Allen allegedly continued tracking details about the dinner, including its schedule.

While traveling cross-country, prosecutors say Allen viewed news coverage about Trump’s planned appearance at the dinner, underscoring how closely he was following developments surrounding the high-profile night.

By April 21, prosecutors say Allen purchased a one-way Amtrak ticket from Los Angeles to Washington, D.C., traveling cross-country with weapons before arriving in the nation’s capital on April 24 and checking into the hotel just hours before the event.

On April 23, while en route from Chicago to D.C., the defendant again used his cellphone to visit the website of a D.C. newspaper to view an article titled "Social Scene: Your Guide to the 2026 White House Correspondents Dinner Weekend."

Prosecutors say Allen admitted in his writings that he "would still go through most everyone" to reach his targets, underscoring the potential for mass casualties.

Breaking Celebrity News reported Allen also allegedly criticized security measures in real time, suggesting he was able to move through parts of the hotel undetected while armed.

A subsequent search of his hotel room and residence uncovered additional weapons, ammunition, and tactical gear, further reinforcing what authorities describe as an extensively planned attack.

Given the severity of the allegations, federal officials say there is "overwhelming evidence" against Allen and are pushing to keep him behind bars, arguing no conditions of release would reasonably guarantee public safety as the case moves forward.

For now, Allen remains in federal custody as prosecutors warn the case represents not just a failed attack, but a chilling example of how close a calculated act of violence came to unfolding at one of Washington’s most high-profile events.