Fantastic truths and where to find them: how do judges decide which witnesses to believe?

By Sarah Murray and Laura Beagrie

It cannot have escaped anyone’s notice that Johnny Depp recently lost his libel claim against the publishers of The Sun newspaper after Mr Justice Nicol held that the allegations made against him of domestic violence were substantially true. Whilst questions over the future of his film career abound, on any view his credibility lies in tatters; with the judgment handed down after a 16-day trial where Mr Depp gave evidence for over 20 hours.

The case turned largely on witness evidence and the credibility, or otherwise of those giving evidence, shedding a light on the difficulty of assessing witnesses and over relying on them in proceedings. Short of polygraph tests, truth serums or time machines, how do judges decide whether witnesses are telling the truth?

The Bingham factors

Lord Bingham, former Master of the Rolls, Lord Chief Justice and Senior Law Lord set out a good starting point for assessing witness credibility in his essay entitled, “The Business of Judging”. Although noting their relative importance will vary widely from case to case, he outlined each of the below factors as the main tests needed to determine whether a witness is lying or not.

Consistency of the witness’s evidence with what is agreed or clearly shown by other evidence 

Evidently, clearly obvious facts and contemporaneous documents provide a useful framework for what has happened. Thus, witness evidence, which is consistent with those “fixed point facts”, is obviously more credible than evidence that is inconsistent.

This is neatly illustrated by the Depp case, especially through a particular incident on an aeroplane. Mr Depp had said that he remembered the flight in detail, however this was contradicted by a text message he sent after the flight in which he said he had blacked out. Additionally, his former personal assistant had also sent a text saying, “He doesn’t remember much”. Whilst Mr Depp and his assistant tried to explain the texts away as being sent to placate Ms Heard, they formed the basis for the judge’s findings that Mr Depp had assaulted Ms Heard on that occasion, that he blacked out at times and that, perhaps because of this, he did not recall the assault until reminded of it.

Witness evidence can also be undermined by metadata (hidden data within documents showing information such as the dates on which they were created or modified). For example, a member of Mr Depp’s security team, Mr Betts, originally stated that he had seen Mr Depp with an injury on 21 April 2016 and had taken a photo of it, which was exhibited to his witness statement. He subsequently amended this to say that the photo attached to the statement was not the one he had taken, although it was similar. In cross-examination it then emerged that the photo had a date stamp of 23 March 2015 (a date on which Ms Heard accepted that she had struck Mr Depp). Due to the inconsistencies in this statement, the judge found Mr Bett’s evidence that he saw an injury to Mr Depp’s face on 21 April 2016 was considerably weakened.

As the smallest inconsistency can be blown up to epic proportions under the microscope of cross examination, the need for witnesses and their legal teams to be completely on top of the detail of a case is vital.

The internal consistency of witness evidence

If a witness gives an account of events during cross-examination which contradicts itself, this obviously raises doubts about the credibility of their evidence. In other legal systems, witnesses can be coached so that they can practice their evidence. However, this is not permitted under English law. The most witnesses can do is to undergo witness familiarisation training, which gives them an understanding of the process of giving evidence and what is expected of them. This may help them to remain calm during cross-examination and minimise the risk of them saying something that they do not really mean.

Consistency with what the witness has said on other occasions

If a witness says something different to what they have said (or not said) on a previous occasion this can obviously damage their credibility. During cross-examination in the Depp case, Mr Depp admitted that he had, or may have, head-butted Ms Heard. Mr Depp agreed that this was a very important detail, but when asked why it was then omitted from his witness statement, he said that he had not noticed that it was not included in his witness statement, saying, “‘I am sure that I read some of [the witness statement]. I do not know that I read it all. With these words, all credibility in Mr Depp’s written witness statements were lost, highlighting the clear need for witnesses to read their statements carefully and to speak up if any amendment is needed.

However, witnesses can take some heart by the fact that inconsistences may not be fatal if they can be legitimately explained. For example, Ms Heard had originally said that Mr Depp had defaced a painting on 8 March 2013, only to subsequently say, having read through the materials again, she had realised the incident had actually happened on 22 March 2013. The judge accepted Ms Heard’s explanation as to how the mistake had come about and her credibility remained intact. 

The credit of the witness in relation to matters not relevant to the litigation

A judge may take the view that if a witness is willing to lie or can be shown to have acted dishonestly in an unrelated matter it is support for the proposition that he or she might be willing to lie or act dishonestly in giving evidence.

In the Depp case, Mr Depp’s lawyers sought to argue that Ms Heard’s alleged dishonesty on other occasions should lead the judge to disbelieve her allegations of domestic violence. These arguments were unsuccessful on the particular facts of the case but evidence of dishonesty on the part of a witness should always be considered carefully for deployment in legal proceedings.

The demeanour of the witness

Due to its subjectivity, this is perhaps the most difficult factor that judges seek to assess. Further, people are not always aware of the extent to which their own and other people’s memories are unreliable, and we believe our memories to be more faithful than they are.

The approach in commercial cases is to treat demeanour of witnesses with caution. In one case, Lord Justice Leggat said that it was a fallacy to suppose that, because a witness has confidence in his or her recollection and is honest, evidence based on that recollection provided any reliable guide to the truth. Instead, best approach was to place little, if any, reliance on witnesses’ recollections of what was said in meetings and conversations, so basing factual findings on documentary evidence and known or probable facts. He saw the value of oral testimony was as a tool to subject the documents to critical scrutiny and to allow a judge to gauge the personality, motivations and working practices of a witness.

Unfortunately, this approach is not always possible as many matters litigated before the courts will not be fully recorded in documents. In such cases, Judges must make findings of fact based upon all of the evidence and where a party’s sworn evidence is disbelieved the court must say why.

Witness familiarisation training can also help with demeanour issues and creating the right impression. Above all, it is sensible for witnesses to keep calm, consider questions carefully, to give considered and thoughtful answers and make concessions when obviously required.

Additional factors for consideration

Importantly, there are other factors that can mean the difference between evidence being believed or not. For example, the independence of a witness can make their evidence more credible, whereas the evidence of clearly partisan witnesses makes their evidence less credible. In the Depp case, few of the witnesses were independent because they were mainly friends, relatives or employees of Mr Depp or Ms Heard. However, the judge did note that one particular witness, Mr Murphy, was “an enthusiastic supporter of Mr Depp”, quoting an email he had written to Mr Depp, which said “I’ll always have your back … anytime/anywhere …”. Less weight was placed on his evidence as a result.

Additionally, Occam’s razor says that the simplest explanation is usually the right one. Judges are likely to deploy this principle, applying a healthy dollop of common sense, when assessing witness evidence. To give an example from the Depp case, in one incident, Mr Depp sought to explain a text to his assistant asking for drugs as being a request for prescription drugs. The judge rejected this on the grounds that, as Mr Depp’s personal nurse was with him at the time, it would make no sense for his assistant to be the source of prescription drugs rather than her.

Preparing the witness

With credibility under the microscope and every statement pored over by the other side and the court to try and trip them up, it may seem like witnesses face an impossible task. However, there are some principles that can be followed to counter this. Whilst it should go without saying that the most important thing for a witness to do is tell the truth, they must also remember that contemporaneous documents are the most important evidence for the fact-finding exercise at trial. Therefore, if a witness is to depart from what they show, he or she needs to be able to explain why.

The preparation of the witness statement is also key. A witness should be closely involved in its drafting and intimately acquainted with its contents, as well as the documents exhibited to it. Any omissions should be discussed and, if necessary, added. Anything that is not completely true, or which could be misinterpreted should be removed.

Witness preparation training is another great way to get into the mindset a good witness needs. Paramount is the principle that the job of a witness is to help the judge find the truth of the case, therefore, a witness who is helpful, open and honest is far more likely to be believed than one that is evasive, combative or slippery with his or her answers.

Assessing the truth or otherwise of witness evidence is notoriously difficult. Memory is fallible, and court are having to increasingly rely on witness evidence, which many are ill-equipped to deal with. However, through thorough preparation and consideration of the intense scrutiny witness evidence will be subject to, witness credibility can be strengthened, helping judges get closer to the truth.

About the Authors

Sarah Murray

Sarah Murray is head of the dispute resolution practice and deals with a wide range of commercial disputes both in the High Court and through arbitration. She trained at a City firm and joined Stevens & Bolton in 2003. She became a partner in 2013.

Laura Beagrie

Laura Beagrie is a highly experienced professional support lawyer who delivers specialist technical support to disputes lawyers across the firm. She helps to develop the practice of the commercial litigation and arbitration team, manages the team’s know-how and precedents and helps deliver its training programme.

The views expressed in this article are those of the authors and do not necessarily reflect the views or policies of The Political Anthropologist.