how do i protect my child from abuse

Father had taken pictures of childs naked bottom, and placedt hem on my space. I went to court and cps ,and the police, and was denied of help.
what do i do to protect my child?
he doesn t want to see his daddy, states his daddy is mean to him. and has done bad things to him, ect.
i have teachers of my childs school that has witness my child talking about what his daddy did.
and know one will help us. we have joint custody.