FOND DU LAC, Wis. (CBS 58) – A convicted child killer known as the “Halloween Killer” appeared in a Fond du Lac courtroom today.

The state is trying to keep Gerald Turner in custody claiming he remains a sexually violent person.

Turner served his time for the sexual assault and murder of 9-year-old Lisa French on October 31, 1973.

Turner was released from prison earlier this year but remains in state custody. Turner’s attorney is appealing the detainment and wants the case moved to Dane County.

A hearing is scheduled for later in April.