A week after the Secret Service director’s disastrous appearance before a House committee, her interim replacement and a top FBI official offered a Senate hearing a more detailed breakdown of the security failures at a rally where former President Trump was shot — and the first potential clues about the shooter’s thinking.

FBI Deputy Director Paul Abbate told a joint hearing of the Senate Judiciary and Homeland Security committees that while the agency still could not establish a clear motive for the July 13 shooting, it is poring over a social media account that could possibly belong to the shooter, Thomas Matthew Crooks, looking for clues.

The account includes several hundred messages with antisemitic and anti-immigration messages from 2019 and 2020 that “espoused political violence and are described as extreme in nature,” Abbate said.

Acting Secret Service Director Ronald Rowe Jr. said before the panel that the shooting “was a failure on multiple levels” for the agency, striking a different tone from his predecessor, Kimberly Cheatle, whose unresponsive and combative answers to a House committee’s questions July 22 sparked bipartisan calls for her ouster. She stepped down as the head of the agency the following day.

Rowe said he and his investigators traveled to the Pennsylvania rally site and lay prone on the same roof where Crooks was when he shot at Trump.

“What I saw made me ashamed,” Rowe said at the hearing about the clear line of sight to the rally stage. “I cannot defend why that roof was not better secured.”

Rowe stressed that the Secret Service has been reviewing its actions leading up to the day of the attack. Since the shooting, Rowe said, the agency has identified gaps in the security detail on the day of the rally and implemented corrective actions.

“I do not believe that inadequate time to plan for this event was a factor in the failure,” Rowe said.

A Secret Service drone was meant to go up around 3 p.m. on the day of the rally but was not operational until around 5:20 because of cellular bandwidth problems.

Sen. Chuck Grassley (R-Iowa) asked, “Why is the Secret Service dependent on local cellular network? Does the Secret Service have a backup plan in place?”

Rowe said questions about whether the Secret Service had got their drone up sooner is “something that has cost me a lot of sleep because of the eventual outcome of the assailant.”

“I have no explanation for it,” Rowe said about why the drone was not operational sooner. “It is something that I feel as though we could have perhaps found him. We could have maybe stopped him. Maybe on that particular day, he would have decided this isn’t the day to do it, because law enforcement just found me flying my drone.”

According to Abbate, who provided a comprehensive timeline of events leading up to the shooting, the FBI has conducted over 460 interviews as part of their investigation.

Evidence of the security failures included a text message thread among local police countersnipers who said they saw a suspicious person around the rally site but failed to approach him, according to reporting from the New York Times.

Rowe emphasized that the Secret Service countersniper teams and members of Trump’s security detail did not know there was a man on the roof of the American Glass Research building armed with a gun.

“It is my understanding those personnel were not aware the assailant had a firearm until they heard gunshots,” Rowe said.

One of the gunman’s bullets grazed the former president’s ear, Abbate confirmed, and in the barrage of gunfire from Crooks, a spectator was killed and two others were wounded. Within seconds of the first shot, Crooks was killed by a Secret Service sniper.

Former President Trump is escorted to a motorcade following an attempted assassination at a campaign event in Butler, Pa., on July 13.

(Gene J. Puskar / Associated Press)

Abbate provided a general timeline leading up to the shooting and some of the factors that led to the security failures.

Crooks registered to attend the rally on July 6, three days after it was announced by the Trump campaign. At that time, he also searched online: “How far was Oswald from Kennedy?”

The following day, he traveled to the Butler venue and walked around for about 20 minutes in what the FBI says was a reconnaissance trip.

A day before the rally, he went to a shooting range at a local gun club.

He arrived at the farm show site around 10 a.m. on the day of the shooting and remained there for about 70 minutes before returning home. While at his home, Crooks’ father gave him a rifle for the purpose he believed of going back to the gun club sometime around 1:30 p.m., Abbate said.

About 25 minutes later, Crooks purchased ammunition on his way back to Butler. He was later spotted walking near the American Glass Research building from which he ultimately committed the attack.

Shortly before 4 p.m., Crooks flew a drone approximately 200 yards from the farm show grounds for about 11 minutes, according to Abbate. The drone and controller were later found in his car.

Investigators say their analysis shows there were no photos or videos taken by the drone, but it was confirmed that Crooks livestreamed from the drone to his controller.

Crooks was first spotted by local law enforcement personnel at 4:26 p.m., and shortly after 5 p.m., he was identified as a suspicious person.

Less than 10 minutes later, a local SWAT officer working the security detail took a photo of Crooks, Abbate said. Crooks was observed next to the AGR building using his phone and holding a range-finder.

By 5:30 p.m., his photo was sent to SWAT members in a group text message.

Approximately 25 minutes before the shooting, the Secret Service command post was notified of a suspicious person, but officers lost sight of Crooks from 6:02 to 6:08 p.m. Law enforcement continued to communicate with each other to try and find him during that span.

Video from a local business shows Crooks pulling himself up onto the AGR building rooftop around 6:06 p.m., and two minutes later, he was spotted by local law enforcement.

A local police officer lifted himself up to the roof where Crooks was positioned at 6:11 p.m. He was able to radio that Crooks was armed with a long gun. Authorities have not been able to determine how the rifle was brought up to the roof and whether it was stored, broken down, in a backpack and put back together on the roof.

Lawmakers repeatedly asked Rowe why Trump was allowed to take the stage if a suspicious person was being pursued by law enforcement.

There was roughly half a minute between when local law enforcement radioed that Crooks had a gun and shots were fired, according to Rowe.

“My understanding is it was not relayed to” Secret Service, Rowe said.

Sen. Josh Hawley (R-Mo.) said that span would still leave time for information to make its way to Trump’s security detail.

Hawley repeatedly pressed Rowe to provide names of Secret Service personnel and whether they have been fired. Rowe said there is an ongoing investigation and he is not “zeroing in on one or two individuals.”

“What more do you need to know that there were critical enough failures that some individuals ought to be held accountable? What more do you need to know?” Hawley asked.

“I need to know is exactly what happened, and I need my investigators to do their job,” Rowe said. “You’re asking me, Senator, to completely make a rush to judgment about somebody failing. I acknowledge this was a failure.”

“A former president was shot,” Hawley said.

“Sir, this could have been our Texas School Book Depository. I have lost sleep over that for the last 17 days,” Rowe said, referring to the 1963 assassination of John F. Kennedy in Dallas.

“Then fire somebody,” Hawley said.

“I will tell you, Senator, that I will not rush to judgment, that people will be held accountable, and I will do so with integrity,” Rowe said.