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

Secret Service Director Kim Cheatle has resigned, according to two sources familiar with the decision.

In the days since the attack, Cheatle and the Secret Service have faced heightened scrutiny for failing to prevent the incident from happening.

Cheatle faced calls to resign from Republicans and Democrats.

"The Secret Service’s solemn mission is to protect our nation’s leaders and financial infrastructure. On July 13th, we fell short on that mission," Cheatle said in a letter to Secret Service employees, obtained by ABC News. "The scrutiny over the last week has been intense and will continue to remain as our operational tempo increases. As your Director, I take full responsibility for the security lapse."

"The Secret Service will move forward with our investigatory and protective mission in a steadfast manner. We do not retreat from challenge. However, I do not want my calls for resignation to be a distraction from the great work each and every one of you do towards our vital mission," Cheatle said, in part. "In light of recent events, it is with a heavy heart that, I have made the difficult decision to step down as your Director."

-ABC News' Luke Barr

Seven Republicans and six Democrats will be on the House task force investigating the Trump rally shooting, House Speaker Mike Johnson and House Minority Leader Hakeem Jeffries said.

The House is expected to vote on a resolution this week to establish the task force and its members.

"The task force will be empowered with subpoena authority and will move quickly to find the facts, ensure accountability, and make certain such failures never happen again," Johnson and Jeffries said in a statement Tuesday.

-ABC News’ Lauren Peller

Sen. Josh Hawley, R-Mo., said Monday that a whistleblower had come forward to his office claiming there was supposed to be a security officer posted on the roof of the building where the gunman fired from, but that that person abandoned the post due to the heat.

The whistleblower, who Hawley said has direct knowledge of the Secret Service's planning for the event, alleged "that there was supposed to be a law enforcement presence on the roof that day," Hawley wrote in a letter to Department of Homeland Security Secretary Alejandro Mayorkas posted on X. "In fact, the whistleblower alleges that at least one individual was specifically assigned to the roof for the duration of the rally, but this person abandoned his or her post due to the hot weather."

Hawley said the whistleblower also alleged that "concerns over the heat prompted law enforcement to forego patrolling" the building and instead station security personnel inside it.

Hawley's letter requests that Mayorkas address the whistleblower's allegations by Friday.

ABC News has reached out to the Secret Service for comment on the letter.

During a hearing before the House Oversight Committee on Monday, Secret Service Director Kim Cheatle said that there was "overwatch" provided for the roof, but did not elaborate, when asked why no agents were placed on the building.

"What I can tell you is that there was a plan in place to provide overwatch, and we are still looking into responsibilities and who was going to provide overwatch," Cheatle said. "But the Secret Service in general, not speaking specifically to this incident, when we are providing overwatch, whether that be through counter-snipers or other technology, prefer to have sterile rooftops."

-ABC News' Allison Pecorin

House Oversight Committee Ranking Member Jamie Raskin, D-Md., called for Secret Service Director Kim Cheatle’s resignation in his closing statement.

"I think that the director has lost the confidence at a very urgent and tender moment in the history of the country, and we need to very quickly move beyond this," he told the other members of the House Oversight Committee following Cheatle’s testimony.

House Oversight Committee Chairman James Comer took Cheatle to task about her transparency.

"I don't believe the American people tonight, when they go to bed, are going to have confidence that the Secret Service is the best it could be at protecting President Biden, at protecting the first lady, at protecting President Trump, at protecting their families," he said.

Local law enforcement alerted the Secret Service of the shooter, Cheatle testified, but she did not elaborate.

Rep. Nick Langworthy, R-N.Y., said Cheatle has put "two black eyes" on her agency and should resign.

"Many people here have called for your resignation. I've introduced a resolution here into this body that hopefully will get a vote this week, calling on the president to fire you," Langworthy said.

House Speaker Mike Johnson met with Cheatle in person ahead of her testimony Monday morning and also told her to resign.

-ABC News’ Luke Barr