A 31-year-old California man accused of opening fire at the White House Correspondents' dinner on Saturday is due in court Monday as lawmakers question security measures at the high-profile event, according to reporting from LEX 18 News.

Cole Tomas Allen of Torrance, California, was apprehended before he could enter the ballroom, which held 2,300 guests including President Donald Trump and numerous cabinet members. Allen allegedly sprinted through a security checkpoint and left behind a manifesto expressing a desire to target top Trump administration officials, according to investigators.

One officer was shot in the bullet-resistant vest during the incident and is expected to recover. Inside the ballroom, attendees heard gunshots before Secret Service agents rushed the stage to protect Trump and other guests.

Acting Attorney General Todd Blanche announced that Allen faces two charges: using a firearm during a crime of violence and assault on a federal officer with a dangerous weapon. Blanche said Allen traveled by train from Los Angeles to Chicago before reaching Washington, D.C., and checked into the event's hotel two days prior to the shooting.

The incident has prompted immediate scrutiny from Capitol Hill. Republican Sen. Chuck Grassley announced plans to request a briefing with Secret Service leadership regarding security protocols and law enforcement activities. Questions have emerged about whether magnetometers at the event were properly positioned and whether the perimeter security was adequate.

Family members told investigators that Allen had a history of making radical statements, according to law enforcement officials. The shooting marks a significant security breach at one of Washington's most high-profile annual events.