Something quite common in German and Austrian law is for the judge to request an expert assessment/report (Gutachtung) on which he or she will use to reach a decision in custody/access cases.
Quite a few of these have in the past been found to be incorrect, simply to not reflect the facts. Here is a case in Austria where a case is being made against an expert for thirteen (!!) incorrect reports. In addition the judge hearing the case has now been dismissed due to prejudice.
All the time the victims are being denied justice.
via Gutachterprozess Dr. Egon B. – Befangenheitsantrag gegen Richterin | Familie & Familienrecht