BSL legal experts are able to advise on the fidelity of BSL police interview transcripts and the quality of police and court interpreters. They are not able to advise on medicolegal, psychological, linguistic or capacity assessments. The overriding duty of an expert witness is to provide independent, impartial and unbiased evidence to legal advocates and/or the courts by way of an Expert Report. Expert witnesses should be engaged based on their knowledge, experience, professional status and legal expertise.