Page 16 - Top Cover Issue 9

16 TOP COVER ISSUE 9

SCIENCE ON THE STREET

The benefits of providing a very early account seem appealing method of investigators. In this respect police witnesses are no
when you look closely at many memory studies that focus upon the different from civilian witnesses.
speed with which memories can be lost. However, many of these The quality and accuracy of details diminishes with tiredness,
studies have not considered the impact that genuine threat and fear physiological arousal and under conditions of divided attention or
can have on a witness’s ability to encode and retrieve information. reduced cognitive resources. Given the vulnerability of memory
Immediate interviewing is the preferred method of evidential under such demanding conditions, the method by which accounts
capture for civilian witnesses of crime and the IPCC wishes to of memory are captured by officers is crucial. Memory is vulnerable
adopt this process for all DSI incidents. However, NPCC makes not only at the time of encoding but also at the point of retrieval.
a distinction that the IPCC does not acknowledge: traumatised Notably, remember poor interview techniques are the leading
individuals may require a period of time to help them remember source of memory contamination in witness evidence.
details prior to providing a full detailed account. Every significant witness should be given the opportunity
NPCC guidance states quite specifically that for civilian to choose between giving their evidence by way of visual
witnesses: ‘Trauma and stress can interfere with the process of recording, producing a detailed statement or an audio recording
remembering and, therefore, decisions about the timing of the as an alternative. The IPCC’s contention that Principal Officers
interview should be made on the basis of the facts of the case and receive preferential treatment misrepresents the current national
by asking the interviewee rather than by application of an arbitrary guidance. Consideration must be given to the Ministry of Justice
period’. recommendation on Achieving Best Evidence (2011) that:
The practice of delaying the full statements finds support within “interviews should not take place at a time when the witness is
research studies involving trained professionals on operational likely to be suffering from the effects of fatigue (other than in the
duty, particularly those where high levels of personal threat and exceptional circumstances).”
arousal have been induced (Military and Police). When considering spoken versus written formats of providing
In addition to the impact of neurohormones (adrenaline and an initial account, the main areas for concern are that (i) the account
cortisol) released during stress and threatening encounters, the is of sufficient detail and quantity, (ii) the person delivering the
ability to recall accurate incident detail may be a function of the account is supported in the type and direction of the information,
amount of time elapsed between the stress exposure and statement (iii) the person is protected from further harm or victimisation
writing. from the process itself, and (iv) the account is protected from
There is a tension between the need for immediacy in eliciting contaminating factors.
accounts of critical events from witnesses, and Witnesses providing written accounts
the need for ‘complete accounts’ in order to have control over the pace and content
preserve the memory of the event. So when Currently there is no of the output with less real or perceived
is the best time to commit yourself to giving pressure to complete the account quickly
a detailed account which could be the most legal stipulation as to just than in oral accounts to an interviewer,
significant statement of your life, and what how any witness ‘should’ where the interactional structure of talk
is the best process to follow – interview or requires a response in a timely fashion, in
statement? or ‘must’ provide their accordance with the cooperative principle of
It should be appreciated that memories conversation.
are reconstructions of people’s experiences of evidential account when Recent UK research reveals that the
events and are not necessarily a faithful record assisting the investigative written accounts of firearms officers contain
of the events themselves. In this respect, consistently low errors, within a range between
they are unlike other recording media such process. 3-7%. Principal Officers do constrain their
as videos or audio recordings, to which they reporting style and only commit in writing
should not be compared (Guidelines on those facts that they are confident to report.
Memory and the Law, 2008). In contrast the purpose of a significant witness interview (ABE)
Any method of obtaining witness accounts significantly is to increase and maximise the amount of detail provided by a
influences both the quality and also quantity of evidence. compliant witness, “please tell us everything you can think of,
Interviewing and statement taking has great potential to induce whether you think it relevant or not.”
errors and misinformation into every account, albeit that this is the The Cognitive Interview (CI) has been shown to increase the
common practice of police forces around the world. quantity of information by some 41%, when compared with
Investigation teams would clearly like as much information standard police interviews (Kohnken, Milne, 1999). However, as
and detail from witnesses as possible their beliefs, perceptions a bye-product of this interview strategy, factual inaccuracies and
and recollections. However, for Principal Officers minimising memory errors sit within a range of somewhere between 15-25%,
the number of errors contained within their accounts is vitally regardless of the experience of the interviewer.
important, safeguarding their legal status as witnesses, minimising This style of interviewing has serious potential implications
ambiguity and lessening the avenues of ‘attack’ from inquest to the status of a ‘firer’, as memory errors increase so a witness’s
lawyers. credibility diminishes.
Currently there is no legal stipulation as to just how any witness Often, oral interviews by detectives with witnesses or victims
‘should’ or ‘must’ provide their evidential account when assisting can be seen as co-constructed accounts by the interviewer and
the investigative process. Every witness is free to choose how he interviewee and are criticised at Court. They involve officers’
or she wishes to provide information regardless of the preferred reformulations of accounts produced by the interviewee, reflecting