This chapter considers how the police and the courts have utilised outside expertise and developed innovative ways to adapt practices so that the environment is better managed, the questioning of vulnerable persons is more appropriate, miscommunication is, therefore, less likely. The word 'vulnerable' has its origins in the Latin vulnerare 'to wound'. The focus on groups that seems to dominate when vulnerable witnesses are considered arises because the law in all the jurisdictions in the United Kingdom is concerned with giving them access to various special measures intended to be of assistance when they give evidence. A great deal of work has been and continues to be conducted into the memory recall, the interviewing of children who are developing within standard parameters. The chapter argues that in practice the meaning of 'vulnerability' depends on the purpose for which it is used. When it is used in relation to the criminal justice system, vulnerability is initially defined with reference to groups.