FBI investigates Trump assassination attempt as domestic terrorism

The FBI noted that the shooter, identified as Thomas Matthew Crooks, acted alone in the attack during Trump's rally.

The US Federal Bureau of Investigation (FBI) said Sunday that it is looking into the assassination attempt against former President Donald Trump during a rally in Pennsylvania as a "potential domestic terrorism act" while noting that the shooter had acted alone.

“At this point (in) the investigation, it appears that he was a lone actor, but we still have more investigation to go,” Robert Wells, the executive assistant director of the FBI’s National Security Branch, told reporters, referring to the suspected shooter, who was identified as Thomas Matthew Crooks, a 20-year-old Pennsylvania man.

"We are investigating this as an assassination attempt but also looking at it as a potential domestic terrorism act," he added.

“So our counterterrorism division and our criminal divisions are working jointly together to determine the motive,” Wells said.

FBI Special Agent Kevin Rojek said the gun used in the assassination attempt was an “AR-style 556 rifle” which was purchased legally.

Crooks was fatally shot by a Secret Service agent after he opened fire from what the agency said was an elevated position outside of the Butler, Pennsylvania field where Trump was addressing his supporters ahead of November's presidential election. Authorities have yet to determine a motive for the shooting.

President Joe Biden said he instructed officials to ensure that the ongoing probe into Saturday's shooting is "thorough and swift" and that investigators "have every resource they need to get this done."