• The House select committee investigating the Jan. 6 Capitol riot sent letters Monday asking three Republican lawmakers to cooperate with the panel and share what they know about the deadly attack.
• The committee said it is seeking information from GOP Reps. Ronny Jackson of Texas, Andy Biggs of Arizona and Mo Brooks of Alabama.
• The committee wants to meet with the lawmakers next week, one month before the investigators plan to start unveiling their findings in a series of public hearings.

The House select committee investigating the Jan. 6 Capitol riot sent letters Monday asking three Republican lawmakers to cooperate with the panel and share what they know about the deadly attack.

The panel said it wants to ask one of those lawmakers, Rep. Andy Biggs of Arizona, about his involvement in planning the events that led to the riot, when a mob of then-President Donald Trump's supporters stormed the Capitol and forced members of Congress into hiding.

Another letter asked Rep. Mo Brooks, R-Ala., to discuss his claim that "Trump asked me to rescind the 2020 elections."

The committee's letter to Rep. Ronny Jackson, R-Texas, included text messages sent during the riot by members of the far-right militia group the Oath Keepers, saying that Jackson "needs protection" because he "has critical data to protect."

The committee wants to meet with the lawmakers next week, one month before the investigators plan to start unveiling their findings in a series of public hearings.

Many House Republicans, especially those most vocally allied with Trump, have railed against the select committee and its two Republican members, including Rep. Liz Cheney of Wyoming.

Jackson, in a defiant statement Monday afternoon, said he would not cooperate with the committee. "I do not know, nor did I have contact with, those who exchanged text messages about me on January 6," his statement said.

Biggs tweeted later Monday that he would also refuse to cooperate. He also called for GOP leadership to remove the select panel's two Republican members, Liz Cheney of Wyoming and Illinois Rep. Adam Kinzinger, "from representing the party in this committee."

A spokesperson for Brooks did not respond to a request for comment.

Jackson and Biggs join other GOP lawmakers who have already defied the panel's requests.

House Minority Leader Kevin McCarthy, R-Calif., rejected the committee's request to voluntarily provide information, saying he had "nothing else to add" to the investigation. But a series of audio tapes, which were recorded shortly after the Capitol riot and leaked last month, showed McCarthy telling Republicans that he would ask Trump to resign as president and worrying about incendiary comments made by his GOP colleagues.

Select committee Chair Bennie Thompson, D-Miss., said last week that the panel still wants to hear from McCarthy in light of the new audio.

"As we work to provide answers to the American people about that day, we consider it a patriotic duty for all witnesses to cooperate," Thompson said in a news release Monday. "We urge our colleagues to join the hundreds of individuals who have shared information with the Select Committee as we work to get to the bottom of what happened on January 6th."

Those hundreds of witnesses include numerous high-ranking officials from the Trump White House. One of Trump's adult children, Ivanka Trump, has already talked to the investigators, and Donald Trump Jr. is reportedly set to voluntarily testify, as well.

The latest requests for cooperation from Biggs, Brooks and Jackson include details about why the committee wants to talk to those lawmakers.

The committee said that Biggs participated in efforts to try to overturn the election on Jan. 6, 2021, when Congress met at the Capitol to confirm President Joe Biden's Electoral College victory. Trump and his allies — who failed in dozens of lawsuits to reverse Biden's wins in key swing states — heaped pressure on Vice President Mike Pence to reject the final vote tallies during the Jan. 6 proceedings. Pence refused.

Biggs also tried to persuade various officials that the 2020 election had been stolen, the panel's letter said. Trump repeatedly and falsely claimed that he beat Biden and that the race had been rigged through widespread fraud.

The committee also hinted at "recent information" regarding an effort from some House Republicans to seek presidential pardons for actions related to the push to overturn the election. "Your name was identified as a potential participant in that effort," the letter to Biggs said.

The letter to Brooks focused entirely on his remarks from earlier this year, when he said that Trump "asked me to rescind the 2020 elections, immediately remove Joe Biden from the White House, immediately put President Trump back in the White House, and hold a new special election for the presidency."

Jackson's letter, meanwhile, said that newly revealed texts raised questions about the congressperson's connection to the Oath Keepers. Some members of that group have been charged with seditious conspiracy and other crimes related to the Capitol riot.

The letter shows texts between three Oath Keepers, including the group's leader, Stewart Rhodes, and two unidentified members.

"Ronnie Jackson (TX) office inside Capitol – he needs [Oath Keeper] help. Anyone inside?" one unnamed Oath Keeper texted at 3 p.m. ET during the riot, according to the letter.

A second unnamed person replied: "Hopefully they can help Dr. Jackson." Five minutes later, the first member posted a photo and wrote, "Dr. Ronnie Jackson – on the move. Needs protection. If anyone inside cover him. He has critical data to protect."

Rhodes then chimed in: "Give him my cell."

The committee said it wants to ask Jackson whom he spoke with on the phone that day. The investigators also want to know why the Oath Keepers were directed to protect him and why they thought he possessed "critical data."