I found out recently on talking to others, that there is act for Vulnerable Persons (1986) and yet when looking at the Act it does not talk about non-verbal persons and how they would be protected as the person attacked ironically has to make some kind of verbal submission.  So we still need changes to the law for those who cannot speak or they are never given justice and their perpetrator is never punished. 

The NSW police did not make special arrangements for my son in fact they did not even meet him or attempt to -  they took my information and my photos of his injury and they went to talk to the respite house but they did not even try to meet James which is remiss on their part and showed their lack of investigaton - usually you should meet the victim.

(NSW Government 2017 - Communities and Justice)

The courts make special arrangements for vulnerable persons who need to appear in court to give evidence.
For details of special provisions please refer to Safety and Protection > Courts - special provisions for 'vulnerable' witnesses

In the Criminal Procedure Act 1986 chapter 6 part 6 a vulnerable person is a person who has suffered a personal assault offence and is one of the following

a child, or
a cognitively impaired person. This includes:
(a) an intellectual disability,
(b) a developmental disorder (including an autistic spectrum disorder),
(c) a neurological disorder,
(d) dementia,
(e) a severe mental illness,
(f) a brain injury.

NSW Police Force definition
The NSW Police make special arrangements for vulnerable persons - particularly when they need to give a statement.

In the Law Enforcement (Powers and Responsibilities) Regulation 2005 Clause 24 a person who falls within one or more of the following categories is a " vulnerable person":

(a) children
(b) people who have impaired intellectual functioning
(c) people who have impaired physical functioning
(d) people who are Aboriginal or Torres Strait Islanders
(e) people who are of non-English speaking background