The justice system should be fair for everyone.
The right to a fair trial is a fundamental human right and a critical element of a fair justice system. Ensuring a fair trial is not limited to what happens in a court room. Many cases never go to court. In cases that do, the stages that came before court can be just as important.
Unreliable evidence presents a significant risk to achieving a fair trial. Its use can result in innocent people being convicted (a miscarriage of justice). Such convictions may, or may not, be quashed on appeal.
Courts have wide powers to exclude evidence where they believe it would have an adverse impact on fairness. Courts can also direct a jury to be cautious about convicting a person the basis of certain evidence. Where unreliable evidence is identified, prosecutions may fail.
Both miscarriages of justice and failed prosecutions involve significant unnecessary expense and wasted time, inconvenience witnesses, distress victims and reduce public confidence in the system.
In order to reduce the risk that evidence is unreliable (and may therefore be excluded), the police are expected to collect evidence in certain ways.
The circumstances which render courts likely to exclude evidence are: -
- breaches of human rights; or
- breaches of the Police & Criminal Evidence Act 1984 and statutory Codes of Practice; or
- where the police act in bad faith (acting in good faith does not excuse breaches).