Sir: Bayney and Ikkos (Psychiatric Bulletin, May 2002, 26, 182-185) provide a helpful outline of the elements of the police decision-making process with respect to referrals of those with mental disorder. However, they make two important omissions. The first, and most significant, is the implication that the decision to prosecute is a police one. It should be emphasised that while the investigation of crime is undoubtedly a core police role, the decision to prosecute lies with the Crown Prosecution Service (CPS) and not with the police force. It is the role of the police to charge an individual if they feel it appropriate and to then refer the case to the CPS for consideration.

Second, the role of the CPS at the pre- and post-charge stages is not included. The Code for Crown Prosecutors (Crown Prosecution Service, 2000) notes that both before referring a case and during the prosecution, the police have a key liaison role. This role involves both discussing cases in which a decision to make a formal CPS referral has not yet been made, and in providing further information to the CPS as a prosecution proceeds. The police and the CPS, although independent of each other, are fundamentally linked, and the omission of the CPS impairs a full appreciation of the process under scrutiny.