When to enable witnesses to provide their own written statements.
Use of self-administered interviews – recommendation
Senior officers in charge of critical incidents or serious crimes should consider use of a self-administered interview in single incidents involving high numbers of witnesses.
Evidence summary
Evidence suggests use of a self-administered interview (SAI) immediately after participants have witnessed an event can increase the overall amount of information recalled, with no impact on accuracy. Evidence also suggested using an SAI can improve the quality of information recalled when questioned again a week later. The evidence is drawn from 13 laboratory-based experiments.
The Guideline Committee agreed an SAI should only be used when witnesses are too numerous for officers/staff to interview them all, and not as a standard alternative to verbal initial accounts.
Using an SAI
An SAI is a standardised set of clear instructions and questions that enable witnesses to provide their own written statements. SAIs may not be suitable for all circumstances and should only be used when it is not feasible to take an initial account verbally. SAIs should not be used as a standard replacement for verbal initial accounts. Senior officers in charge of critical incidents or serious crimes should make decisions about deploying an SAI based on the scale of an event and number of available witnesses. A particular use for the SAI could be as a triage measure to identify key witnesses with whom to conduct follow-up enquiries. Computer-based SAI packages are readily available.
The committee felt that witnesses should complete the SAI form in the presence of police officers or staff and should not be allowed to take it away. They felt this was important in case the witness needs support and to minimise the risk of misinformation and non-completion. The committee also felt care should be taken to ensure the SAI is administered to those who will be able to read and understand its instructions. Some SAI packages have a computer-generated voice that speaks the question to assist respondents who require support with reading.
Research indicated the benefits of using an SAI are only realised if used immediately or very soon after the event. It is not recommended to use an SAI if substantial time has passed since the event.