Jury members (jurors) are selected for jury service at random by computer from the electoral register (a list of all the people in the UK who are registered to vote in political elections). Everyone on the electoral register between the ages of 18 and 70 is eligible, and around 500,000 are selected at random by computer every year. You cannot do jury service if you are on bail, have been convicted of a criminal offence, or if you suffer from a mental disorder.

Each jury is composed of 12 jury members. Juries are only used in criminal cases (although they are sometimes used in civil libel claims - see section on judges) and their role is to decide whether the defendant is guilty or not. They do this in a special jury room outside the court after they have heard the evidence. The foreman/forewoman (one of the 12 jurors) will then tell the judge the verdict that the jury has reached. The judge will then give out the sentence.