(NEXSTAR) – Pennsylvania State Police (PSP) commissioner Colonel Christopher Paris testified before the House Homeland Security Committee Tuesday on the attempted assassination of former President Trump.

During questioning, Paris revealed that two officers who were at a post inside a building that overlooked the rooftop from which Thomas Matthew Crooks attempted to assassinate former President Trump left their station shortly before Crooks went up to the roof, The Hill reports.

The officers were both SWAT-trained members of the Butler Emergency Services Unit (ESU), and were the first to flag Crooks as suspicious when he didn’t enter the venue with the rest of the attendees before Trump’s speech, according to an investigation by the PSP.

Paris said that the two officers left their post to go search for Crooks on the ground “alongside other local officers in the immediacy after Crooks had been identified as a suspicious person.”

“Are you then saying from your knowledge that those ESU officers left the location where they could look out the window in search of this person?” Rep. Dan Bishop (R-N.C.) asked Paris.

“Yes, that is my understanding,” Paris responded.

When asked if the two officers would have had a clear shot at Crooks on the rooftop, Paris said that he wasn’t sure. A video shown during the hearing suggested that they would have, however.

Paris’ testimony came one day after lawmakers grilled Kimberly Cheatle, then-director of the Secret Service. On Tuesday, Cheatle resigned from the post despite asserting the day before that she was the “right person” to lead the Secret Service.

“I take full responsibility for the security lapse,” she said in an email to staff obtained by The Associated Press. “In light of recent events, it is with a heavy heart that I have made the difficult decision to step down as your director.”

Cheatle’s departure was unlikely to end the scrutiny of the long-troubled agency after the failures of July 13, and it comes at a critical juncture ahead of the Democratic National Convention and a busy presidential campaign season. Lawmakers on both sides of the aisle have promised more investigations, along with an inspector general probe and an independent and bipartisan effort launched at President Joe Biden’s behest that will keep the agency in the spotlight.

Cheatle’s resignation came a day after she appeared before a congressional committee and was berated for hours by both Democrats and Republicans for the security failures. She called the attempt on Trump’s life the Secret Service’s “most significant operational failure” in decades, but she angered lawmakers by failing to answer specific questions about the investigation.

Biden said in a statement that “what happened that day can never happen again,” and he said he would appoint a new director soon, but he did not discuss a timeline.

The president said he was grateful to Cheatle for her decades of public service. “We especially thank her for answering the call to lead the Secret Service during our administration, and we are grateful for her service to our family,” Biden said.

Homeland Security Secretary Alejandro Mayorkas appointed Deputy Director Ronald Rowe as acting director. He has worked for the Secret Service for 23 years.

The Associated Press contributed to this report.