Trump shooting updates: Shooter flew drone 200 yards from site hours before shooting

Sen. Chuck Grassley, R-IA, has released body-camera footage his office obtained from the Beaver County Emergency Services Unit taken soon after the assassination attempt on Donald Trump.

The graphic video, posted to X, shows a number of law enforcement officers standing on the roof where the shooter took his perch. The body of the deceased shooter is still there as the officers discuss the incident.

Grassley said the video was obtained in compliance with congressional requests.

"Bodycam footage provides more info than Secret Service will share w America," he said in the post. "We NEED detailed answers ASAP on security failures TRANSPARENCY BRINGS ACCOUNTABILITY."

The Secret Service has recommended that Trump's campaign stop holding rallies outdoors following the assassination attempt, sources familiar with the matter told ABC News.

The Washington Post first reported the news.

None of the rallies planned in the coming days are scheduled to be held outdoors. Conversations about upcoming rally sites have not included any outdoor venues, the sources said.

A campaign spokesperson did not immediately comment.

-ABC News' John Santucci, Katherine Faulders and Luke Barr

The new acting director of the Secret Service, Ron Rowe, pledged to "restore the faith and confidence of the American public and the people we are entrusted to protect" in a message to the agency workforce.

Rowe also mentioned Secret Service Director Kim Cheatle's resignation, saying, "This agency owes her a debt of gratitude that can never be repaid. Our organization is a better place because of her nearly three decades of service."

It was only "a matter of seconds" between the time that the gunman, Thomas Matthew Crooks, had been positively identified as a threat with a gun -- as opposed to just a suspicious person -- and when he first opened fire, Pennsylvania State Police Col. Christopher Paris told the House Homeland Security Committee on Tuesday.

Paris said Crooks was identified as a "suspicious" person because he was staying outside the venue perimeter and not entering the venue, and he was "milling around" the area in front of the AGR building, where he later fired from. But at that point, Crooks was just one of four people "identified as suspicious" at the Trump rally, Paris said.

When Butler County ESU members saw Crooks had a rangefinder, "the suspicion was heightened," and they sent that information and a photo of him to state police inside the command post, who "immediately" relayed it "verbally" to Secret Service, Paris said. State police also sent the photo of Crooks to a Secret Service number, he said.

That was about 20 to 30 minutes before Crooks opened fire, Paris said.

"But at that point. just to be clear, he was determined to be suspicious," Paris emphasized. "There was no information that he possessed a weapon."

The ESU members at the AGR building and at least two municipal officers in the area then "were actively looking for Crooks," Paris said.

"They circled the building, but then it became apparent at some point that he was on the roof," Paris said.

So one of the municipal officers "boosted the other one up, hanging from the ledge of the roof," he said. "By the time that officer was boosted up on top of the roof, Crooks was on it, almost in that final position that you saw, he had the AR out, and he pointed it at the municipal officer who was suspended from the roof. [The officer] was not in a position -- feet dangling at that point --- to draw a weapon. ... He let go, and he fell back down."

Meanwhile, other law enforcement was scrambling on the ground to find the suspicious person but couldn't see him on the roof, Paris said.

It was "a matter of seconds" between the officer falling and Crooks opening fire, Paris said.

-ABC News’ Luke Barr and Mike Levine