Inside a trial: roles, juries and proof

In a criminal trial, a person's freedom may be at stake. The system has rules to make trials as fair as possible.

Practise this lesson free (6 questions)

Innocent until proven guilty

In a criminal trial the defendant is presumed innocent until proven guilty.
The prosecution must prove guilt beyond reasonable doubt: the jury or magistrates must be sure.
In civil cases the standard is lower: the balance of probabilities (more likely than not).
In England and Wales, the Crown Prosecution Service (CPS) decides whether to charge someone and prosecutes most criminal cases brought by the police.

Who's who in the Crown Court

Each person has a role:
PersonRole
JudgeRuns the trial, decides points of law and passes sentence
JuryDecides the facts: guilty or not guilty
DefendantThe person accused of the crime
ProsecutionLawyers who try to prove the defendant is guilty
DefenceLawyers who represent the defendant
WitnessesPeople who give evidence about what they saw or know

Juries and lawyers

Jurors in England and Wales are aged 18 to 75, chosen at random from the electoral register. Jury service is a civic duty.
The judge may accept a majority verdict, such as 10 to 2, if the jury cannot all agree.
Solicitors give legal advice and prepare cases; barristers usually argue cases in the higher courts.
Legal aid can help people who cannot afford a lawyer, especially in criminal cases.
Worked example

Why must the prosecution prove guilt 'beyond reasonable doubt' rather than 'more likely than not'?

  1. A guilty verdict can take away someone's liberty and give them a criminal record.
  2. Convicting an innocent person is a very serious injustice.
  3. So the system sets a high standard: the jury must be sure.

Answer: Because the consequences of a wrong conviction are so serious, the jury must be sure before finding someone guilty.

Key idea

Defendants are presumed innocent. In criminal cases guilt must be proved beyond reasonable doubt; civil cases use the balance of probabilities. The judge decides the law and sentence; the jury decides guilty or not guilty. Jurors are 18 to 75 and chosen at random.

Key words
Jury
A group of 12 members of the public, chosen at random, who decide whether a defendant is guilty in the Crown Court.
Majority
More than half. A party with a majority in the Commons has at least 326 of the 650 MPs.

All KS3 Citizenship key terms and definitions →

Common mistakes
Quick check

Try two quick questions

See if it has sunk in. Answers are marked straight away.

Extra practice

2 more questions

Try each one, then tap to check.

  1. What does the presumption of innocence mean?

    1. A defendant must prove they are innocent
    2. The police decide who is guilty
    3. All defendants are guilty
    4. A defendant is treated as innocent until proven guilty
    Show the answer

    Answer: A defendant is treated as innocent until proven guilty

    The prosecution must prove guilt; the defendant does not have to prove innocence.

  2. What is the standard of proof in a civil case?

    1. Beyond reasonable doubt
    2. Absolute certainty
    3. On the balance of probabilities
    4. Whatever the jury feels like
    Show the answer

    Answer: On the balance of probabilities

    Civil cases use the balance of probabilities; criminal cases need proof beyond reasonable doubt.

Check you have got it

Answer 6 quick questions with instant marking. If you get one wrong, GCSE-ready shows you why and gives you another go. It is free, and you do not need an account.

Practise this lesson free (6 questions)All KS3 Citizenship lessons

Video for this lesson coming soon. Subscribe on YouTube

Sources and references

Checked by the GCSE-ready editorial team, 16 October 2026. Last updated 2 October 2026. Spotted a mistake? Tell us and we will fix it.