Evidence
Evidence determines what a court may consider and how much weight it carries. A sergeant must understand relevance, admissibility, the exclusion of unfairly obtained evidence, hearsay, confessions, identification evidence, and the chain of custody for exhibits.
Concepts to master
- Relevance is the threshold; irrelevant evidence is inadmissible however reliable.
- Hearsay is generally inadmissible, subject to exceptions.
- Confessions: voluntariness, the effect of inducements, and the significance of custody safeguards (access to a solicitor, caution, recording).
- Identification: Turnbull-style warnings; weakness of eyewitness identification.
- Corroboration and the dangers of relying on a single source.
- Continuity of exhibits: who had the item, when, and how it was sealed and stored.
Traps
- Assuming a technical breach automatically excludes evidence - the test is fairness of the trial.
- Treating a confession as conclusive.
- Failing to record continuity, breaking the chain.
Rule of thumb
Apply the RACCC check for any exhibit or statement: Relevance, Admissibility, Continuity, Corroboration, Challenge. Worked example: a drug seizure is only as strong as its continuity - if the bag was unsealed and unattended overnight, the defence will attack the chain, and the sergeant must be able to account for every handover.