Shooter reportedly used a ladder to gain access to roof in Trump assassination attempt

As government officials continue to investigate what took place Saturday when a gunman fired multiple shots toward former President Donald Trump, The Associated Press reports officers were warned by rally attendees of a man acting suspiciously.

Citing an unnamed law enforcement source, rally attendees also advised officers that the gunman, later identified as Thomas Matthew Crooks, used a ladder to gain access to the rooftop he used to fire multiple rounds toward Trump.

Crooks was fatally wounded by authorities seconds after he fired toward Trump, officials said. Trump had a wound to his ear, but his campaign said he was "fine."

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In an interview with CNN, Butler County Sheriff Michael Slupe said one of his officers encountered the shooter, but was unable to stop him.

"The officer got lifted up to the roof, and when the eye contact was made, my understanding is the shooter turned towards the officer and the officer dropped his grip and fell to the ground at that point," Slupe said. "And I'm assuming… that the shooter then started shooting shortly thereafter."

The shooter's ability to get on a rooftop nearly 150 yards from Trump with a clear line of sight is prompting numerous questions over how the Secret Service handled security at Saturday's rally.

"A direct line of sight like that to the former president should not occur," Homeland Security Secretary Alejandro Mayorkas told ABC News' "Good Morning America" on Monday. "That's why President Biden directed an independent review of the incident."

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U.S. Secret Service Director Kimberly Cheatle said the agency would agree to the review.

While the Secret Service has the task of protecting current and former presidents like Trump, the agency calls upon local officers to assist with security. Slupe defended the actions of his officers.

"You're not going to be so many feet away to give the shooter an opportunity to shoot you," he told CNN. "So the officers absolutely did what they needed to do and what they're trained to do."