A federal judge on Thursday dismissed all charges against a man convicted of lying to U.S. immigration officials about his whereabouts during the 1994 Rwandan mass killings, ending a case that was the first in America to require proof of genocide.

Prosecutors earlier in the day asked U.S. District Judge Monti Belot to set aside Lazare Kobagaya’s visa fraud conviction and dismiss a charge of lying during his citizenship application.