How does a criminal trial actually run?
Through a defined sequence designed around a single principle: the prosecution must prove its case, and the defendant does not have to prove anything.
Before the trial. Charge, first appearance, plea, and — for cases going to the Crown Court — a preparation hearing. Disclosure happens here: the prosecution must disclose material that undermines its case or assists the defence, which is a continuing duty and a recurring source of appeals when it fails.
The trial sequence:
Jury selection, in the Crown Court, from a randomly summoned panel.
The prosecution opening, outlining what it says happened and what it will prove.
Prosecution evidence — witnesses examined in chief, then cross-examined by the defence, then re-examined.
A submission of no case to answer, which the defence may make if the evidence could not support a conviction.
Defence evidence, which may include the defendant giving evidence — they are not obliged to, though a jury may in defined circumstances draw an inference from silence.
Closing speeches from both sides.
The judge's summing up, directing the jury on the law and reminding them of the evidence. The judge decides law; the jury decides facts — that division is the structure of the whole thing.
Deliberation, in private, with a direction to reach a unanimous verdict; a majority verdict may later be accepted.
Verdict, then sentencing — frequently adjourned for reports.
The principles that govern it:
The burden is on the prosecution, to the standard of beyond reasonable doubt — expressed to juries as being sure.
The defendant is presumed innocent.
Hearsay and character evidence are restricted, with exceptions.
Reporting restrictions apply, and commenting publicly on an active case can be contempt.
Magistrates' court differs: no jury, magistrates or a district judge deciding both law and fact, limited sentencing powers, and the great majority of cases resolved there.
Most cases never reach trial, resolving through guilty pleas — which attract a sentence reduction that reduces with lateness.
General information, not legal advice.