This guide is maintained as a current resource for July 2026 and covers only the laws of England and Wales. Information is for general guidance, not legal advice. Consult a qualified solicitor for advice specific to your situation.
Learn how police evidence is presented in criminal trials in England and Wales. This guide explains how police prepare, disclose and give evidence, the role of witnesses, exhibits, expert reports, admissibility rules and how evidence influences trial outcomes.
In criminal trials in England and Wales, evidence gathered by the police forms a central part of the prosecution's case. How that evidence is prepared, disclosed and presented in court affects the fairness, clarity and outcome of a trial. This article explains how police evidence enters a criminal trial, the types of evidence used, the rules governing admissibility, the role of witness testimony, and practical considerations for defendants and legal teams.
Introduction
Police officers investigate reported or suspected criminal offences. Their investigations generate evidence - from witness statements to physical exhibits and expert reports - which the prosecution, typically the Crown Prosecution Service (CPS), uses to build a case against an accused person. Presenting police evidence in court is not simply a matter of producing material; it involves strict procedural steps, compliance with statutory rules and court authority on what evidence may be admitted. This process ensures that trials are fair and that all parties understand the case against them.
What Counts as Police Evidence?
Evidence refers to information or material presented in court that tends to prove or disprove a fact relevant to the case. In a criminal trial, police evidence often includes:
- Witness statements - accounts from victims, witnesses or police officers about what they observed.
- Physical exhibits - objects, documents, recordings or other tangible items linked to the alleged offence.
- Forensic and digital evidence - scientific analyses such as DNA, fingerprints, digital data from devices or CCTV footage.
- Expert reports prepared on behalf of the prosecution following police investigations.
Each category must be properly prepared and admissible under criminal procedure rules before it can be considered by the judge or jury.
Preparation and Disclosure of Evidence
Before a trial, police compile material gathered during the investigation and hand it to the CPS. The prosecutor then applies legal tests to decide whether there is sufficient evidence to charge the suspect and, later, to prosecute. A key part of this process is disclosure - providing the defence with material relevant to the case.
Under disclosure rules, the prosecution must give the defence:
- Used material - evidence the prosecutor intends to rely on at trial.
- Unused material - evidence that is relevant, undermines the prosecution case or assists the defence, even if it will not be used at trial.
This often includes witness statements, exhibits and forensic reports. Police help the CPS prepare these materials, often on MG6 schedules, which list prosecution evidence for the court and defence teams.
The objective of disclosure is to avoid “trial by ambush”, ensuring the defence has an adequate opportunity to prepare responses and challenge evidence where appropriate.
Witness Statements and Testimony
Police officers are often called as witnesses to give oral evidence about what happened during the investigation. Witness testimony is typically central to presenting police evidence:
Written Statements
Before trial, police and other witnesses usually prepare written statements that describe what they observed. These statements may be served on the defence and the court ahead of trial. In some cases, where agreed with the defence, a written statement can be read in court under section 9 or section 10 of the Criminal Justice Act 1967. Under section 9, the statement is read as evidence if the defence does not object; under section 10, an agreed version of evidence becomes conclusive on specific facts.
Oral Evidence (Giving Evidence in Person)
At trial, police officers or other witnesses provide evidence by speaking in court under oath or affirmation. They give their account in response to questions from the prosecutor and then face cross‑examination by the defence. This live testimony gives the jury or magistrates the opportunity to assess credibility and reliability directly.
Use of Live Links and Special Measures
Where a witness is vulnerable or there are practical reasons, courts can allow evidence to be given via live audio or video link under provisions of the Criminal Justice Act 2003. This can also apply to police officers or victims, where agreed and in the interests of justice.
Exhibits and Physical Evidence
Physical items or exhibits are crucial in many trials. These can include clothing, weapons, documents, recordings or other objects relevant to the alleged offence. Police must retain exhibits and manage an audit trail proving continuity and integrity from seizure to court production. The CPS usually takes responsibility for arranging exhibits to be in court and ensuring they are produced when required.
Once an item is introduced in evidence, it may be shown to witnesses who will identify it and explain its significance during their testimony. Proper handling helps prevent challenges based on lost or tampered evidence.
Expert Evidence
Some evidence requires technical interpretation beyond lay understanding. In such cases, police or prosecutors may instruct expert witnesses - for example, forensic scientists - to prepare reports or give opinions in court. Expert evidence is admissible where it provides information likely to be outside a judge's or jury's experience and directly assists in understanding material issues. Expert reports must be disclosed before trial and comply with Criminal Procedure Rules on content and transparency.
Admissibility and Legal Challenges
Not all evidence collected by the police will be admissible in court. The judge will consider whether the evidence is:
- Relevant - logically probative of a fact in issue.
- Admissible under law - obtained and presented in compliance with statutory rules and without undue prejudice.
For example, evidence obtained in breach of the Police and Criminal Evidence Act 1984 (PACE) or judged overly prejudicial may be excluded under section 78 PACE. This ensures that the defendant receives a fair trial, balancing probative value with fairness.
Jury and Judicial Considerations
In trials before a jury, the judge directs jurors on how they should treat certain kinds of evidence, including police testimony and exhibits. The jury decides whether to accept police evidence and how much weight to attach to it, while the judge oversees legal admissibility issues and instructions on legal standards like burden and standard of proof.
Practical Considerations
For defendants and legal representatives:
- Defence teams review all disclosed evidence before trial and identify areas to challenge through legal argument or cross‑examination.
- Police officers appearing as witnesses should prepare by reviewing their statements and relevant investigation records.
- Understanding the sequence and basis of police evidence helps defence solicitors and barristers frame effective defence strategies.
Key Takeaways
- Police evidence in criminal trials includes witness statements, physical exhibits, forensic and digital evidence prepared during investigation.
- Evidence must be disclosed to the defence and the court, with rules designed to ensure fairness and adequate preparation.
- Police or other witnesses give oral evidence in court, with opportunities for cross‑examination.
- Exhibits are managed carefully to maintain integrity.
- Expert evidence may supplement police evidence where specialised knowledge is required.
- Judges control what evidence is admitted, balancing relevance and fairness under procedural rules.
