WASHINGTON — House Republicans on Thursday began their promised investigation into whether people charged with crimes in connection with the Jan. 6 attack on the Capitol have been mistreated in jail, fulfilling a pledge G.O.P. leaders made to their right flank.
The investigation — part of a broader effort by Republicans to rewrite the history of the riot in part by portraying participants as the true victims — has been a top priority of Representative Marjorie Taylor Greene, Republican of Georgia.
On Thursday, Ms. Greene wrote to the D.C. mayor, Muriel Bowser, demanding answers to questions, a tour of the correctional facility in southeastern Washington, and access to staff and inmates to conduct interviews by March 23. She and two other lawmakers also asked for all documents and communications about the Jan. 6 detainees’ complaints regarding the conditions.
“Eyewitness accounts of conditions at the D.C. jail facilities — particularly regarding the treatment of Jan. 6 detainees — paint a picture of despair, hopelessness, and a severe abuse of justice,” Ms. Greene wrote in the letter, which was also signed by Representative James R. Comer, Republican of Kentucky and the chairman of the Oversight Committee, and Representative Clay Higgins, Republican of Louisiana. “No prisoner in the United States should be treated in this fashion.”
The investigation comes as Republicans, two years after the mob attack at the Capitol, have split over Jan. 6. Many in the party regard the riot as a political liability and would like to focus on economic or other policy issues. But a louder group wants to relitigate it publicly to feed the anger of the party’s hard-right base, which reveres former President Donald J. Trump and believes the rioters were justified in standing up against an election he falsely claims was stolen.
Understand the Events on Jan. 6
Ms. Greene visited the jail in November 2021 and detailed her findings in a report released the next month. She said one inmate reported being beaten by other detainees and not being provided care. Another showed evidence of having a fractured bone that was left untreated, she said.
Civil rights advocates have long been concerned about conditions at the D.C. jail. But they received increased attention after the Jan. 6 attack, when a few dozen of the arrestees began being housed there.
Their lawyers raised concerns about threats from guards, standing sewage and scant food and water. A federal judge held top officials of the D.C. jail in contempt of court, ruling they had improperly delayed medical treatment for a defendant kept in their custody in connection with the Jan. 6 attack.
The lawmakers said they were focused on whether Jan. 6 defendants were receiving worse treatment than other detainees. Ms. Greene said detainees told her they had been denied access to a Bible and Communion because they had refused to take the coronavirus vaccine.
The investigation at the jail is one of several demands made by right-wing lawmakers as Speaker Kevin McCarthy, Republican of California, sought their votes during weeks of intense negotiations in his campaign for the top job in the House. In a closed-door meeting of Republicans in November, right-wing lawmakers including Ms. Greene extracted a promise that their leaders would investigate Speaker Nancy Pelosi and the Justice Department for their treatment of defendants jailed in connection with the Jan. 6 attack.
Mr. McCarthy also authorized the release of more than 40,000 hours of Capitol security footage from Jan. 6, 2021, to the Fox News host Tucker Carlson, who used the video to attempt to play down the violence of Jan. 6 and recast the attack as a largely peaceful gathering.
Mr. McCarthy also has authorized a subcommittee to investigate the events surrounding the Capitol breach, warning the House committee that investigated Jan. 6 last year to preserve its files. He appointed Representative Barry Loudermilk of Georgia, a Republican he views as being unfairly maligned by the Jan. 6 panel, as the chairman of a House Administration subcommittee assigned to investigate security failures and review the House Jan. 6 committee’s work for signs of bias.
Jonathan Swan contributed reporting.