Prosecutors have charged a man and a woman from Fergus Falls with murder in the death of a six-year-old boy they were caring for. 40-year-old Bobbie Bishop and 44-year-old Walter Wynhoff are charged with second-degree murder, manslaughter and malicious punishment of a child. The boy was unresponsive when he was brought to a Fergus Falls hospital Monday. An investigator noted the boy’s body was covered with sores, cuts, and scratches. According to charging documents, Wynhoff said the boy had been taped to a wall with duct tape while Bishop said she spanked the boy with a belt about 20 times in the last monthBishop said she began caring for the children of a friend in August. A sibling was taken into protective custody.