FIRST ON FOX: A top House committee is launching an investigation into the U.S. government's plea deal with the three alleged terrorists behind the Sept. 11, 2001 terror attacks.

Chairman Mike Rogers, R-Ala., of the House Armed Services Committee, wrote to Defense Secretary Lloyd Austin on Thursday demanding documents related to the plea deal, including "all documents and communications containing terms, conditions, agreements, side-deals, or any mutually developed, related, conditional, or linked agreements with any party relating to terms and conditions of the plea agreements."

Rogers also asked for records of communications spanning the Biden administration regarding the plea deal, which he called "unconscionable."

"I, along with much of our nation and Congress, are deeply shocked and angered by news that the terrorist mastermind and his associates who planned the September 11, 2001 terror attacks, which killed nearly 3000 innocent people, were offered a plea deal," Rogers wrote in the letter, first obtained by Fox News Digital. 

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Mike Rogers on 9/11 plea deal

House Armed Services Committee Chairman Mike Rogers, left, is demanding more information on the plea deal for Khalid Shaikh Mohammad and two other 9/11 defendants. (Getty Images)

"Tragically, the news is a 'gut punch' to many of the victims’ families." 

It comes after the Pentagon announced that three alleged plotters of the Sept. 11 attacks, who were awaiting trial in Guantánamo Bay, Cuba, entered into pretrial agreements with the U.S. government.

The details of the plea deals for Khalid Shaikh Mohammad, Walid Muhammad Salih Mubarak Bin Attash and Mustafa Ahmed Adam al Hawsawi were not immediately made public.

The three are accused of providing assistance, including training and financial support, to the al Qaeda hijackers who crashed passenger jets into the World Trade Center towers in New York City and the Pentagon in Arlington, Virginia, nearly 23 years ago.

Another plane, thought to be aimed at the U.S. Capitol, crashed into a field in Shanksville, Pennsylvania, after passengers and crew overwhelmed the terrorists. Everyone aboard was killed.

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The Pentagon building

The Pentagon building in Arlington, Virginia, on Friday, April 21, 2023. (Tom Brenner/Bloomberg via Getty Images)

"It is unconscionable that the Biden-Harris Administration would allow such a plea deal. You, Mr. Secretary, are the Cabinet Member with ultimate oversight of the Office of Military Commissions. Your Department allowed a plea deal with Khalid Shaikh Mohammed and his band of killers," Rogers wrote Thursday.

"Deals like this give hope to terrorists throughout the world that America is not willing to hold the worst of the worst accountable for their wicked crimes. In short, this deal signals willingness to negotiate with terrorists who deliberately harm Americans."

The Pentagon declined to comment on the letter when asked by Fox News Digital, explaining, "As with all congressional correspondence, the Department will respond directly to the Members."

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Rogers' investigation comes as the House Oversight Committee launched a parallel probe into the plea deals, with Chairman James Comer, R-Ky., writing a letter to President Biden on Friday.

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Brett Eagleson, the president of a grassroots group made up of victims' families called 9/11 Justice, said he was "deeply troubled" by the plea deals in a statement on Thursday.

"While we acknowledge the decision to avoid the death penalty, our primary concern remains access to these individuals for information. These plea deals should not perpetuate a system of closed-door agreements, where crucial information is hidden without giving the families of the victims the chance to learn the full truth," Eagleson said.