(Bloomberg) — Former Trump campaign official Rick Gates asked a judge to spare him from prison, put him on probation and order him to do community service for his crimes of conspiracy and lying to federal investigators.In a court filing Monday, Gates said he has accepted responsibility “in every way possible.” He’s scheduled to be sentenced by U.S. District Judge Amy Berman Jackson in Washington on Dec. 17.Gates was a critical witness in special counsel Robert Mueller’s investigation of Russian interference in the 2016 U.S. election. He was the star prosecution witness in the trial of his former boss Paul Manafort, who was convicted of bank and tax fraud in August.Gates was Manafort’s right-hand man in his political consulting firm and worked with him for a decade, lobbying on behalf of Ukraine before joining him on Trump’s presidential campaign. Gates remained on the Trump campaign after Manafort resigned in August 2016.He also testified in the trials of one-time White House counsel to Barack Obama, Gregory Craig, and Republican operative Roger Stone.Gates said his “cooperation likely represents the most extensive undertaking by any cooperating defendant in the work of the OSC or any matters arising out of, or related, to the activity of that office.”Additional and specific details of Gates’s cooperation are under seal, according to the filing.Nine letters of support from family and friends, urging Berman to show leniency, were included with the filing. Many described him as a religious man, committed to his family. One letter was filed under seal.Gates also asked that the judge doesn’t impose a fine.“Mr. Gates has remained unemployed since his indictment, and in lieu of any income with which to support his family and maintain their home, he has had to deplete savings and investment accounts, including college savings plans for his children,” according to the filing.The case is U.S. v. Richard W. Gates III, 17-cr-201, U.S. District Court, District of Columbia (Washington).(Updates with letters of support)To contact the reporter on this story: Joe Schneider in Los Angeles at firstname.lastname@example.orgTo contact the editors responsible for this story: David Glovin at email@example.com, Joe Schneider, Peter BlumbergFor more articles like this, please visit us at bloomberg.com©2019 Bloomberg L.P.