A person providing interpretation services. Interpreters in criminal proceedings are expected to have knowledge of police and court procedures; ideally they will be selected from the National Register of Public Service Interpreters, or the Council for the Advancement of Communication with Deaf People Register of Sign Language. It is the responsibility of the police or investigating agency to arrange for interpreters for any part of an investigation, and for the requirements of the suspect, or person charged, while in custody. The court is responsible for arranging the interpreter for the defendant at court, except where the first court appearance is within two days of the charge when the police or prosecuting agency will make the arrangements on its behalf. Normally, the interpreter used in the investigative stage will not be used in court proceedings. The prosecution and defence are responsible for arranging interpreters for their own witnesses. Generally, a separate interpreter is required for each defendant.