Acting Secret Service Ronald Rowe said on Tuesday he “cannot defend” why the rooftop where a gunman attempted to assassinate former President Donald Trump was not “better secured.”

The admission came as Rowe delivered his opening statement during testimony before the Senate’s Judiciary and Homeland Security committees to give testimony about the security lapse.

Rowe said one of his first actions as acting director was to visit Butler, Pennsylvania, and examine the location where the shooting took place earlier this month.

“I went to the roof of the AGR building where the assailant fired shots and I laid in a prone position to evaluate his line of sight,” he said.

“What I saw made me ashamed,” Rowe added. “As a career law enforcement officer, and a 25-year veteran with the Secret Service, I cannot defend why that roof was not better secured.”

Rowe also said it was his understanding the Secret Service’s counter-sniper teams and Trump’s security detail did not know the assailant was on the roof with a firearm until they heard gunshots.

“Prior to that, they were operating with the knowledge that local law enforcement was working an issue of a suspicious individual prior to the shots being fired,” he said.

Questions have been raised about how the gunman, identified as a 20-year-old man named Thomas Matthew Crooks, managed to get onto a nearby rooftop and begin shooting with a rifle.

A Secret Service sniper shot and killed Crooks while other personnel rushed to protect Trump and escort him off the stage, but not before the former president got hit in the right ear.

One rallygoer, 50-year-old fireman Corey Comperatore, was killed. Two others were wounded and have been released from the hospital in recent days.

Secret Service Director Kimberly Cheatle resigned last week, one day after testifying before the House as she faced backlash over the security failure underlying the Trump rally shooting.

Homeland Security Secretary Alejandro Mayorkas then announced that Rowe, the Secret Service’s deputy director, would become acting director.

Rowe said on Tuesday that it was clear to him that “other protective enhancements could have strengthened our security” at the rally and listed some directives he made.

The acting director said he ordered the “expanded” use of drones to detect elevated threats and directed resources to “facilitate” communications, particularly with state and local partners.

Rowe said he directed protective detail requests to be approved “expeditiously” and ordered the “maximum use” of requested personnel at protective sites to address “this heightened security environment.”

The Secret Service’s Office of Professional Responsibility is conducting a review, and any employee shown to have violated agency protocols “will be held accountable to our disciplinary process,” Rowe said.

Rowe also declared that he instructed staff to provide “full cooperation and respond expeditiously on a continuing basis” to congressional investigations.