Autopsy results have been released in the case of a northeast Iowa teenager accused of killing his grandparents. The Delaware County Attorney says the Manchester couple found dead in their home Sunday afternoon were shot to death.

County attorney John Bernau revealed Wednesday afternoon that an autopsy shows Richard Sweet and his wife, Janet Sweet, died of gunshot wounds. Further details are not being released at this time, including the type of gun used in the killings and whether the gun was recovered.

The Sweet’s grandson, 17-year old Isaiah Sweet, is charged in their deaths and remains in custody at the Delaware County Jail. According to court documents, Sweet admitted to a female friend last Friday night that he drugged his grandparents and thought they were dead. He called her again the next morning to tell her he had killed them. Sweet allegedly admitted the killings to two others over the weekend as well.

By Jon Swisher, KMCH, Manchester

Radio Iowa