The first-degree sexual assault charges against the boy came after a 5-year-old girl's mother suspected a game of playing doctor between the two kids had gone too far last fall, the Milwaukee Journal Sentinel reported Thursday.
The parents' lawsuit, filed in federal court in Madison, seeks damages and an injunction against Grant County District Attorney Lisa Riniker. The suit also names a sheriff's deputy and a social worker as defendants.
The lawsuit states the boy, identified as D in the suit, the girl and the girl's 5-year-old brother were playing doctor when the girl's mother walked in. The girl's mother told investigators she suspected D had put his finger in the girl's anus.
D's parents, identified in the suit as Jennifer and Kurt D., said D had a medical condition prior to the play date that required rectal exams.
The Wisconsin State Journal reported in the spring that a judge rule against dismissing a juvenile court petition for protective services filed by Riniker last November. The report stated the girl said D only touched the outside of her buttocks.
Karen and Kurt D's lawsuit contends the whole investigation was biased because the girl's father is a "well-know political figure in Grant County," and that former Grant County Sheriff's Sgt. James Kop "waged a relentless campaign to discredit and embarrass and humiliate 6-year-old D."
The suit also claims Riniker tried to coerce D's parents into signing a consent decree by insinuating she would have the boy removed from their custody.