WASHINGTON — Lawyers for Michael T. Flynn, President Trump’s first national security adviser, asked a federal judge late Tuesday to spare him prison time for misleading investigators, and they suggested that the F.B.I. agents who interviewed him last year at the White House had tricked him into lying.

Mr. Flynn’s lawyers said that his contrition, lengthy military service and willingness to aid the special counsel, Robert S. Mueller III, should warrant a sentence of only probation. “His cooperation was not grudging or delayed,” Mr. Flynn’s lawyers wrote in a sentencing memo that included letters from supporters vouching for his character.

But the lawyers offered no explanation for why Mr. Flynn lied to agents about conversations he had during the presidential transition in late 2016 with the Russian ambassador, Sergey I. Kislyak. And even in accepting blame, Mr. Flynn portrayed himself as a victim of F.B.I. tactics to trap him. His lawyers highlighted details from the interview that played into an unfounded theory that Mr. Flynn’s demeanor during questioning was potential evidence that he did not lie to investigators.

Their emphasis on the F.B.I.’s conduct during the interview aligns with Mr. Trump’s dim view of federal law enforcement. The president has denounced the Russia investigation as a “witch hunt,” and one of his lawyers broached the prospect of a pardon for Mr. Flynn last year as he was weighing whether to cooperate with Mr. Mueller’s investigators.