666. Non-Adversarial Methods of Proving Customary Laws. The proof of Aboriginal customary laws can be a difficult and sensitive problem, not necessarily suited to the adversary system which is at the basis of the present law of evidence and procedure. To overcome this difficulty, alternative methods of proof, notably the use of court experts and assessors, have sometimes been suggested. In overseas jurisdictions extensive use has been made of assessors, and to a lesser extent court experts, as an aid to the proof of customary law. Assessors have also been tried on an experimental basis in Australia. This Chapter examines the role of court experts and assessors and considers their appropriateness in the proof of Aboriginal customary laws. The related question of pre-sentence and similar reports in Aboriginal customary law cases is also raised.