WASHINGTON — Federal prosecutors said in a court filing on Tuesday that despite his long litany of crimes, the former Trump campaign aide Rick Gates deserved leniency because he provided incriminating information against powerful figures amid intense pressure, including promises of payments if he refused to cooperate with investigators.
Mr. Gates, 47, pleaded guilty in February 2018 to a criminal financial conspiracy and to lying to federal prosecutors. Nonbinding sentencing guidelines suggest he should receive 46 to 57 months in prison.
But prosecutors said they did not oppose Mr. Gates’s request that he be sentenced to probation because he had cooperated extensively with the Justice Department under extremely stressful circumstances. He had resisted “pressure not to cooperate with the government, including assurances of monetary assistance,” they wrote.
Prosecutors did not reveal who offered to pay him or any other details, but a person familiar with the matter said that it was most likely a reference to funds raised for Mr. Trump’s legal cases that one of the president’s lawyers had once discussed designating for Mr. Gates and the onetime Trump campaign chairman Paul Manafort.
Mr. Gates, who served as President Trump’s deputy campaign chairman in 2016 and helped manage his inaugural committee, met with prosecutors or investigators more than 50 times, they said. He provided information that was used in more than a dozen search warrants. He also testified for the prosecution in three trials, two of them against Mr. Trump’s friends and former aides.
Roger J. Stone Jr., a longtime friend of Mr. Trump, was convicted of lying to Congress and other crimes and now awaits sentencing. Mr. Manafort is serving a prison term of more than seven years for tax fraud, bank fraud and other offenses.
In the third case, Gregory B. Craig, President Barack Obama’s former White House counsel, was acquitted on charges of lying to avoid registering with the Justice Department as a foreign agent. Mr. Gates has also cooperated with a federal inquiry into Mr. Trump’s inaugural committee.
“Gates’s cooperation has been steadfast despite the fact that the government has asked for his assistance in high-profile matters against powerful individuals in the midst of a particularly turbulent environment,” the prosecutors wrote in an 18-page sentencing memo.
“He should be commended for standing up to provide information and public testimony against individuals such as Manafort, Craig and Stone, knowing well that they enjoy support from the upper echelons of American politics and society,” they said.
While they did not recommend any specific sentence, the prosecutors said Mr. Gates had earned a more lenient sentence than the guidelines suggest.
The prosecutors acknowledged that Mr. Gates had committed more crimes than the two felonies to which he pleaded guilty. Although much of his criminal activity involved executing financial schemes that benefited Mr. Manafort, he also devised schemes to enrich himself, they said.
“Gates engaged in a pattern of deceit over an extended period of time,” they stated.
Among other offenses, he failed to report more than $3 million in income, failed to disclose his foreign bank accounts, committed mortgage fraud and stole several hundred thousand dollars from Mr. Manafort.
Mr. Gates’s lawyers argued in a filing late on Monday that he should be spared prison time.
Mr. Gates will be sentenced on Dec. 17 in United States District Court in Washington by Judge Amy Berman Jackson. She is deeply familiar with his case because she presided over the trials of Mr. Stone and Mr. Craig. She also oversaw one of the two federal prosecutions against Mr. Manafort.
Maggie Haberman contributed reporting from Hershey, Pa.