Jose Luis Castillo is due in federal court in Grand Rapids on Thursday for a hearing on a complaint against him. He's accused in the killing and beheading of Maria Elena Mata Hernandez.
U.S. prosecutors want the extradition request moved ahead for a final decision.
Defense lawyer Donald Garthe said his client, who is serving eight to 15 years in prison for third-degree sexual assault in Berrien County, denies killing his wife. He noted that the complaint names "Jose Luis Castillo" as the suspect, while his client's name is Raul Luis Castillo Jr.
The government says he uses both names.