The Law and Sufficient Evidence

When deciding whether an individual who is accused of an offence should be prosecuted, the Crown Prosecution Service will apply two tests to the case:

• Is there sufficient evidence to secure a conviction?
• Is a prosecution in the public interest?

The question of public interest is only likely to arise if there is sufficient evidence for an individual to be found guilty at trial. Any trial is costly both in terms of time and money. As these costs are paid out of the public purse they can only be justified if a conviction can be secured.

Evidence comes in many different forms including: witness statements; confessions; items found at the scene; and, samples of bodily fluids.

Admissible Evidence

Not all evidence can be used in court against the accused. There are different reasons why evidence may not be allowed but, broadly, inadmissible evidence falls into two categories:

• Types of evidence that are never, or not usually, admissible. For example: evidence from phone-tapping is currently inadmissible but there are moves to change the law so that it can be used; hearsay evidence – the court cannot rely on evidence which consists of someone saying, “I know John did it because Jim told me that he did”.
• Evidence that is not allowed because of the way it was obtained. For example: a confession given during an interview which was improperly conducted; a breath test taken with a faulty machine.

Sometimes a judge will give permission for evidence, which might otherwise have been inadmissible, to be used. This will usually be because the judge has been persuaded by one of the lawyers that the evidence is so valuable that it must be used.

Evidence of Character – Good or Bad

The basic rule is that the Prosecution is not allowed to mention any previous convictions of the accused. The fundamental principle of criminal law is that a person is innocent until proven guilty – regardless of whether they have been in and out of prison all of their lives or have come straight from a convent. However, there are two main cases where previous convictions may be used in a trial:

• The offence has very specific or unusual elements which are known to be common to previous offences the accused has committed. For example, if a burglar is known to always dress up as a clown before breaking into a fried chicken take-away to steal the takings and this is precisely what the defendant has been accused of, his previous convictions may become relevant.
• The defendant “puts character in issue”. If the Defence presents the accused as an upstanding citizen who simply could not have done what he is accused of, they are telling the jury that the defendant’s character is a factor which is relevant to their verdict. The Prosecution are then allowed to use evidence of character to rebut this portrayal of the accused and they may tell the court about any previous convictions.

Burden of Proof

In a criminal trial the Prosecution has to be able to prove the case against the accused beyond reasonable doubt. This means that the jury, in a Crown Court trial, or the magistrates, in a trial in the Magistrates’ Court, must be sure that the accused is guilty. If they are not sure, or if they think that the accused may or may not be guilty, they will have to find him not guilty.

The question of evidential sufficiency is one which will continue throughout the trial process until a verdict has been returned. For example, the Prosecution will sometimes decide just before a trial starts – or even after it has started - that there is insufficient evidence against the accused. This could be because some new evidence which supports the defendant has come to light or because doubt is cast on an important piece of prosecution evidence. It could even be because an important piece of evidence has been lost.

Sufficient Evidence to Rebut a Defence

If an individual accused of an offence such as assault claims that they were acting in self-defence there will be a further test of evidential sufficiency. Not only must there be enough evidence to prove all the elements of the offence – there must also be enough evidence for the Prosecution to disprove the defence.

When self-defence is raised at trial the defendant only has to put forward enough facts to suggest that he may have been acting in self-defence. The Prosecution, however, has to prove beyond reasonable doubt that the Defendant was not acting in self-defence.