Michelle Costello and her 19-year-old son, Peter, will remain in the Atlantic County Jail for 30 days while officials wait for a warrant from Nevada.
They're wanted by Las Vegas police in connection with the Sept. 20 slaying of Costello's 65-year-old husband, Bert English.
The mother and son were arrested Saturday at Resorts Atlantic City after a casino customer recognized them from the "America's Most Wanted" program.
Atlantic County Prosecutor Ted Housel said neither waived extradition during a brief hearing Wednesday and a new court date will be scheduled.
Neither has retained a lawyer.