Dieuseul Jean was nabbed in New Jersey after digital fingerprints allegedly confirmed his identity.
He is now being extradited back to Canada to face charges.
Jean has been on an RCMP most-wanted list.
He is wanted in connection with the killing of his spouse, 42-year-old Juthlande Pierre, who disappeared from a party on Christmas Day 1995.
The woman's body was found beneath carpets in the basement of a Montreal apartment on Jan. 15, 1996. She had been struck repeatedly in the head, with a knife.
Meanwhile, Jean disappeared. The RCMP said he might have been using a handful of aliases over the years.
He is now 52.