SIOUX CITY, Iowa — A Sioux Falls man charged in connection with the death of his 14-year-old niece has waived his right to a detention hearing, opting to remain in federal custody. After pleading not guilty to all charges late last month, defense counsel for Mark Milk filed a notice with the court on July 29 indicating that Milk would give up his right to contest prosecutors’ request that he remain in federal custody. Milk is charged in connecti…