The suspected gunman in the shooting at the White House Correspondents’ Dinner was charged Monday in federal court with three counts including attempting to assassinate the president.

Cole Allen, 31, of Torrance, California, is charged with:

• Using a firearm during a crime of violence;
• Transportation of firearm in interstate commerce with intent to commit a felony;
• Attempt to assassinate the president of the United States. 

President Trump was evacuated after shots rang out at the annual media dinner, which was packed with more than 2,500 politicians, journalists and celebrities on Saturday night. Authorities said a Secret Service agent was struck by a round but was protected by a bulletproof vest and has since been released from the hospital.

Security officers were able to apprehend the suspect, who was evaluated at a local hospital before being moved to a D.C. jail. 

Federal prosecutors noted Monday that Allen traveled across “multiple state lines” with firearms, which federal prosecutor Jocelyn Ballantine identified as a 12-gauge pump action shotgun and a .38 semi-auto pistol, as well as three knives.

Authorities said over the weekend that Allen had traveled by train from Los Angeles to Washington, D.C. 

U.S. Attorney Jeanine Pirro initially said Saturday night that Allen would be charged with using a firearm during a crime of violence and assault on a federal officer using a dangerous weapon, and said additional charges were likely Monday. 

“It is clear, based upon what we know so far, that this individual was intent on doing as much harm and as much damage as he could, and thankfully, because of the checkpoint right outside the ballroom where thousands of people were situated to hear the president of the United States, that checkpoint worked,” Pirro said. “There was no one who was injured, but it was clear where this defendant was going.”

The FBI is conducting a criminal investigation, and the Secret Service is investigating the suspect’s background to understand what precipitated the shooting.

Acting Attorney General Todd Blanche told “Face the Nation with Margaret Brennan” on Sunday that investigators believe the suspect was targeting Trump administration officials. 

CBS News obtained a copy of what investigators described as a “manifesto” written by Allen that he sent to family members. In his alleged writings, Allen said he planned the attack because he didn’t want the “crimes” of the administration to “coat [his] hands.” He didn’t refer to Mr. Trump or the event by name, but allegedly said he intended to target administration officials “prioritized from highest-ranking to lowest.”