Police need more advice for interviewing vulnerable witnesses, researchers say

The University of Portsmouth study is the first to examine the challenges of interviewing people with dissociative identity disorder (DID), a complex disorder characterised by two or more distinct personality states.

The researchers focused on intermediaries and found limited experience of DID, a lack of research and no legal guidance for officers.

Lead researcher Dr Brendan O’Mahony said: ‘There has been a substantial amount of psychological research about the appropriate questioning of children and people with an intellectual disability.

‘However, there has been limited research on how mental disorder and mental distress impacts on effective investigative interviewing.

‘There is certainly a lack of guidelines for professionals on effective questioning of these vulnerable complainants, both at police stations and court.’