Federal prosecutors have added more overdose deaths to the case against a south-central Kansas doctor and his nurse wife. An indictment made public Thursday links the Haysville clinic of Dr. Stephen Schneider and his wife, Linda, to 68 overdose deaths as part of a conspiracy. The couple are directly charged with contributing to 21 of those deaths. The Schneiders were charged in December 2007 on 34 counts alleging they unlawfully prescribed drugs, overbilled for medical services and committed money laundering. The revised charges include some patients who died after the couple were in jail. The Schneiders contend they are innocent and that the federal government is improperly interfering in the doctor-patient relationship. A new trial date is expected to be set.