Democratic leaders are demanding answers after the Department of Justice abruptly reduced the recommended sentence for Roger Stone on Tuesday following President Donald Trump’s public criticism of the length of his longtime adviser’s original recommended sentence.

All four federal prosecutors who ran Stone’s trial dropped out of the case earlier Tuesday after senior Justice Department leadership intervened to walk back the prosecutors’ sentencing recommendation, a rare step that marked the latest sign of Trump’s appointees further politicizing the department in charge of federal law enforcement.

In a newer memo, the U.S. Attorney’s Office for the District of Columbia said an 87- to 108-month sentence for Stone “could be considered excessive and unwarranted,” neglecting to recommend another specific length of time in prison.

NBC reported on Thursday that Attorney General William Barr has become unusually and personally involved in a number of investigations of interest to Trump.

Senate Minority Leader Chuck Schumer (D-N.Y.) sent a letter to the Justice Department’s inspector general requesting an investigation and subsequent report regarding the department’s decision to reduce Stone’s sentencing recommendation.

JUST IN: Senate Minority Leader Schumer sends letter to DOJ inspector general requesting an investigation into the reduced sentencing recommendation for Roger Stone. https://t.co/ZUCwZUPk3p pic.twitter.com/tZDrxXcg3I — NBC Politics (@NBCPolitics) February 11, 2020

“This situation has all the indicia of improper political interference in a criminal prosecution,” Schumer wrote to Inspector General Michael Horowitz. “The American people must have confidence that justice in this country is dispensed impartially. That confidence cannot be sustained if the president or his political appointees are permitted to interfere in prosecution and sentencing recommendations in order to protect their friends and associates.”

House Speaker Nancy Pelosi (D-Calif.) joined Schumer’s calls for an investigation later Tuesday evening, saying Trump “engaged in political interference” via tweet in Stone’s sentencing.

“It is outrageous that DOJ has deeply damaged the rule of law by withdrawing its recommendation,” she tweeted. “Stepping down of prosecutors should be commended & actions of DOJ should be investigated.”

By tweet @realDonaldTrump engaged in political interference in the sentencing of Roger Stone. It is outrageous that DOJ has deeply damaged the rule of law by withdrawing its recommendation. Stepping down of prosecutors should be commended & actions of DOJ should be investigated. — Nancy Pelosi (@SpeakerPelosi) February 12, 2020

Prosecutors Aaron S.J. Zelinsky, Adam C. Jed, Jonathan Kravis and Michael Marando told the court on Monday that Stone should receive seven to nine years in prison. But overnight, the president raged on Twitter against the proposed sentence, calling it a “miscarriage of justice” that could not be allowed.

The Justice Department ― led by Trump appointee Barr ― then reportedly overruled the career prosecutors, walking back their sentencing request and prompting them to resign from the case.

Eric Holder, who served as attorney general during the Obama administration, said the Justice Department’s decision to seek a shorter sentence for Stone is “unprecedented, wrong and ultimately dangerous.”

AUSA’s Kravis and Zelinsky have shown more guts-and an adherence to the rule of law-than too many now serving in Washington. What Main DOJ is trying to do-and at whose behest?-is unprecedented, wrong and ultimately dangerous. DOJ independence is critical https://t.co/NWRMxtohK9 — Eric Holder (@EricHolder) February 11, 2020

The prosecutors who resigned on Tuesday “have shown more guts - and an adherence to the rule of law - than too many now serving in Washington,” Holder tweeted. “DOJ independence is critical.”

A jury convicted Stone in November on charges that included witness tampering, lying to Congress and obstructing an official proceeding. Stone was one of Trump’s highest-profile allies to face prosecution in response to former special counsel Robert Mueller’s investigation into Russian interference in the 2016 election.

A Justice Department spokesperson told Fox News that the decision to reduce Stone’s sentencing recommendation was made before Trump tweeted his disdain and that the department has not had contact with the White House on the matter.