Thomas Gore, seen leaving the District’s federal courthouse after pleading guilty last May (Katherine Frey/The Washington Post)

Federal prosecutors on Friday requested a six-month prison sentence for Thomas Gore, a longtime friend and former campaign aide of Mayor Vincent C. Gray who admitted last year to participating in a 2010 scheme to secretly pay off a minor mayoral candidate.

Gore pleaded guilty last May to a felony count of destroying records related to the federal investigation of the Gray campaign’s dealings with Sulaimon Brown — the fringe candidate paid to verbally attack incumbent Adrian M. Fenty on the campaign trail. Gore, who handled the campaign’s day-to-day finances, also admitted to campaign finance violations connected to the payoffs to Brown.

In a court filing meant to guide the July 26 sentencing decision of U.S. District Judge Colleen Kollar-Kotelly, prosecutors gave Gore credit for a disadvantaged background, a long history of community service and his taking responsibility for his crimes in requesting a sentence at the very minimum suggested by federal guidelines.

The six-month prison term should be followed by six months of home detention, prosecutors said, bringing it within the 12-to-18-month advisory sentencing range.

The prosectuors’ sentencing request came a day after federal investigators said they uncovered that a city accounting firm had funneled illegal contributions to scores of political campaigns, including Gray’s 2010 effort. The mayor has repeatedly denied any wrongdoing.

But Friday’s filing, signed by U.S. Attorney Ronald C. Machen Jr. and Assistant U.S. Attorney Ellen Chubin Epstein, said Gore’s conduct remained “extremely serious” and deserved a prison sentence, saying it “caused significant damage to the image and integrity of the District’s electoral process.”

“Gore’s crimes are made more egregious by the fact that Gore was well aware of the dictates of the local campaign finance laws and knowingly chose to violate them,” the prosecutors wrote, noting he had served as a finance official on Gray’s previous campaigns. “Against this backdrop, his blatant disregard for the campaign finance rules supports the imposition of a significant penalty.”

Gore, they added, later destroyed a notebook that recorded payments made to Brown, then “chose to mislead, obfuscate, and outright lie” in interviews with investigators.

During a pre-sentencing interview with the federal probation office, Gore said he had acted “in the interest of helping a long-term friend who was running for office,” presumably referring to Gray. A friend of Gore’s told the officials had “lost himself in loyalty” to a friend.

Said prosecutors, “An expression of true loyalty . . . would have involved putting an end to the campaign’s illegal conduct before it started, rather than facilitating it. Preserving the integrity of [Gray]’s campaign and saving the campaign from the shame of future, scandalous revelations would have been a far better way for a person in Gore’s position to demonstrate loyalty to his longtime friend.”

The government requested additional conditions, including completing 400 hours of community service and a prohibition on participating in “any political campaign without the prior written approval of the probation department.”

Gore’s attorney, Frederick D. Cooke Jr., declined to comment Friday. He is expected to file his own memorandum offering sentencing guidance to Kollar-Kotelly next week, in which he will likely argue for a lighter sentence.