• The House Jan. 6 committee issued requests for evidence from government agencies Wednesday. 
• It included a request for information on Trump's "mental stability" after the Capitol riot.
• After the riot, Pelosi had called on the Cabinet to remove Trump using the 25th Amendment. 

The House January 6 committee is seeking information on President Donald Trump's mental stability at the time of the insurrection and whether the Cabinet considered invoking the 25th Amendment to remove him from office. 

The panel is investigating the period from Election Day to President Joe Biden's inauguration on January 20, when Trump refused to concede defeat and claimed that the election was stolen from him.

The baseless theory had inspired supporters to attack the Capitol, temporarily halting the certification of Biden's win. 

On Wednesday, the House select committee issued a sweeping request for documents from executive branch agencies including the National Archives, the Department of Defense, the Department of Justice, the Department of Homeland Security, the Department of the Interior, the FBI, the National Counterterrorism Center, and the Office of the Director of the National Intelligence. 

Among the information the lawmakers sought were "all documents and communications related to the mental stability of Donald Trump or his fitness for office," the committee said in a letter to the US National Archives and Records Administration.

This part of the investigation focuses on the period from January 6 to January 20, the date of Biden's inauguration. 

In the wake of the Capitol riot, House Speaker Nancy Pelosi called for Trump to be removed from office under the 25th Amendment, which allows the Cabinet and vice president to remove the president if a majority deem them unable to discharge their duties.

The panel is also requesting from that same period "all documents and communications related to the Twenty-Fifth Amendment to the US Constitution."

The commission's central aim is to "uncover the facts about January 6th and its causes and to help ensure such an attack on American democracy cannot happen again."

Trump hit back at the commission in a Wednesday statement, saying: "The Leftist 'select committee' has further exposed itself as a partisan sham and waste of taxpayer dollars with a request that's timed to distract Americans from historic and global catastrophes brought on by the failures of Joe Biden and the Democrats."

The January 6 commission was launched in June in a mostly party-line vote by the Democratic-controlled House. Republicans had blocked an attempt to form an independent commission modeled on the 9/11 commission to investigate the attack.

Senate Minority Leader Mitch McConnell at the time argued that it was a partisan exercise that would be unnecessary given the investigations that were already being conducted into the attack.