NEW LONDON, Conn. (WFSB) - New London police played a key role in the investigation into a shooting at the White House Correspondents’ Dinner after the suspect’s brother called authorities.

Cole Allen, 31, charged a security checkpoint armed at the White House Correspondents’ Dinner on Saturday night. The brother of the suspect could live in New London and called police after the shooting happened.

Channel 3’s Law enforcement analyst and retired state police Lt. J. Paul Vance called the incident an act of terrorism.

“He was trying to attack White House officials, people that run our country. And that’s unacceptable behavior,” Vance said.

Allen was met by a multi-layered security approach at the checkpoint.

“It was very, very effective and prevented tragedy from occurring. And it came dangerously close, but it was prevented,” Vance said.

Two hours after the shooting, New London police received a call from someone claiming to be the suspect’s brother. According to the Associated Press, that person was then interviewed by New London police and federal investigators.

Allen had written to his family members just before shots rang out in Washington, D.C. In those writings he described himself as a “friendly federal assassin” and made reference to President Donald Trump along with complaints about the administration’s actions.

“They got that information, they got it to the proper, proper authorities. And, and I’m sure that the FBI and, and, uh, the agencies involved in DC, uh, have that carved out as being an investigatory path,” Vance said.

Vance said the case demonstrates the importance of reporting suspicious activity to police.

“It could be something as simple as a suitcase in an airport or a box outside, something, you know, anything,” Vance said. “Every single human being plays a role in that. And that’s what happened here in our state of Connecticut.”

Over the next several days, federal investigators will be looking through Allen’s background and retracing every step he took as he made his way to Washington, D.C.