A Fond du Lac man who spent a long time in prison for sexual assault will remain in custody. Following a two day trial a Fond du lac County jury found 55 year old Donald Anderson to be a sexually violent person. Anderson will be committed to the Sand Ridge Treatment Center in Mauston. In 1994 Anderson was convicted in Fond du Lac County Circuit Court of first degree sexual assault of a child and spent 20 years in prison.
