On Sunday evening Channel 4 began a five part series in which a ‘murder’ will be “authentically tried by a team including eminent practicing QCs, a genuine judge and a jury of 12 members of the public. The only actors include the accused – a man who is pleading not guilty for the murder of his wife - the deceased, and some of the witnesses”.

The quality of the participants is unquestionable: Max Hill QC is the recently appointed Independent Reviewer of Terrorism Legislation; John Ryder QC an eminent silk; and His Honour Brian Baker CBE QC formerly a senior circuit judge.

Perhaps understandably, verisimilitude is sacrificed in the editing suite with the ‘evidence’ partially presented via staccato vignettes. In the first episode this system has been deployed to show the audience snippets of the Simon Davies’ (the defendant) interviews under caution.

The programme begins with the defendant receiving the advice that he should answer, ‘No Comment’ to all questions put to him during his interview. This is closely followed by the interviewing officer noting that, “today is your chance to give your side of the story”.

The officer’s comment is one which defence practitioners hear week in, week out. So, adopting a juror’s question, why no comment?

To start, background is needed. In criminal proceedings the burden of proof falls on the prosecution – they must satisfy a jury so that they are sure that the defendant committed the alleged offence.

Prior to an interview under caution the suspect will be told, “You do not have to say anything. But it may harm your defence if you do not mention when questioned something which you later rely on in Court. Anything you do say may be given in evidence.”

Before an interview under caution a suspect and/or his lawyer is entitled to receive pre-interview disclosure, i.e. “sufficient information to enable [the suspect] to understand the nature of [the offence under investigation] and why they are suspected of committing it”. The sufficiency of pre-interview disclosure is a common battle ground between solicitors and those interviewing.

This caution can be broken down into three parts: 1) A suspect is entitled to remain silent (or reply, ‘no comment’) during the interview; 2) However, if the defendant fails to mention a fact on which reliance is placed at trial then the jury may draw an such inferences as appear proper; 3) The interview will be recorded and the interview, or a transcript of the interview, may be given as evidence in trial.

A defendant cannot be convicted wholly, or mainly, on the strength of any adverse inference which is drawn.

Disclosure can be phased over a number of interviews and at each point a solicitor must balance whether they have sufficient information to properly advise their client; whether (on the information known at that stage) there is a need to establish the factual background upon which the defendant will rely; or whether there is a need to establish a defence at an early stage (most frequently the defences of consent or duress).

The solicitor must also consider whether their client can withstand the rigours of an interview. While an officer may gently comment that this is the suspects ‘opportunity to tell their side of the story’ that is far from the reality.

The interview will test a suspect’s account, the investigating team will consider the detail of the account and any inaccuracies will be magnified when they are deployed at court as ‘inconsistencies’ in the defendant’s account.

In The Trial, Ms Davies is murdered on 24 September. Mr Davies is spoken to at the scene and is described by the officers as ‘traumatised’ and ‘in shock’.

Mr Davies first interview occurs later that day. He appears to be unrepresented and it is not clear whether he received any pre-interview disclosure. The interview lacks formality as it is akin to a chat. Mr Davies speaks freely and in doing so, unnecessarily, describes what may be seen as a motive for murder – his wife’s infidelity which caused the end of his marriage and his departure from the family home while the adulterer moves in.

This information, albeit freely volunteered, is highly unlikely to be a fact upon which the defence rely and there is unlikely to be an inference drawn from its omission. The account is unnecessary and damaging – the effect will be to build a prosecution case theory: the jilted husband.

Mr Davies’ second interview is dated 27 September - three days after Mr Davies was taken into police custody. In this interview Mr Davies is represented and appears to answer by way of a prepared statement (in which he will outline the facts upon which he will rely while answering no comment to all other questions). Prepared statements allow a controlled factual account to be given by a suspect without the waylaying of tangential questions.

On 24 September, Mr Davies’ presentation was of shock and trauma. If he had been represented at the first interview then his solicitor could ensure that an independent medical practitioner undertook an examination to ascertain whether he were fit to be interviewed.

On the facts known in episode one, it appears that it was inadvisable for Mr Davies to answer questions during his first interview as the investigation will have be in a nascent state with an undeveloped case theory and Mr Davies’ answers do not appear to have assisted him in establishing the factual basis of any defence. It is also brave advice for Mr Davies to reply via a prepared statement during his second interview as the representative will not have known the precise detail of Mr Davies’ initial account and, after three days of confinement in custody, Mr Davies’s recall may be partial at best.

An interview under caution is not an opportunity to ‘tell your side of a story’; in contrast, it is a key stage in a criminal investigation in which the interviewee is the suspect. The inference which can be drawn is designed “to deter late fabrication and to encourage early disclosure of genuine defences”. The simplistic, but popular, construct of ‘no comment’ answers being indicative of guilt is misconceived; however, it is a misconception which leads many suspects to answer questions in adverse circumstances. Getting the right advice at an early stage is crucial.