People with disabilities are at high risk of becoming victims of crimes. Those individuals with little or no functional speech (LNFS) are even more at risk of being victims of crime. One way of reducing the risk of being a victim of crime is facing the alleged perpetrator in court as a witness; therefore it is important for people with LNFS who have been victims of crimes to have the relevant vocabulary needed to testify in court. The aim of this study was to identify and describe the legal core vocabulary required by illiterate victims of crime, who have little or no functional speech, to testify in court as witness/witnesses. A mixed method, exploratory sequential design consisting of two different phases was used to address the aim of the research. The first phase was qualitative and included two different data sources, namely in-depth semi-structured interviews (n=3) and focus groups (n=22). The overall aim of this phase was to develop a measurement instrument. Results from Phase 1 were used in Phase 2, the quantitative phase, in which the measurement instrument (a custom designed questionnaire) was socially validated by 31 participants. The results produced six distinct categories which represented the core legal vocabulary and 99 words that represented the fringe legal vocabulary. The findings suggested that each communication board should be individualized to the individual and the specific crime. Recommendations were made to develop an AAC Resource Tool Kit to assist professionals involved with a person with LNFS who had been a victim of crime.