Weight of Evidence
Definition
The persuasive value the fact-finder assigns to evidence after it has been admitted. Weight is a jury or magistrate question, not a judicial one. Chain-of-custody breaks most often reduce weight rather than bar admission.
- Field
- Law of evidence
- Decided by
- Fact-finder, jury or magistrate, not the judge
- Distinct from
- Admissibility, which is a judicial gatekeeping question
- Common effect of custody breaks
- Reduces weight rather than barring admission
- Related concept
- Chain of custody as a legal construct
Common questions
If a chain-of-custody gap does not exclude evidence, what does it actually accomplish for the defence?+
It gives the defence grounds to argue in front of the jury that the evidence is less reliable, opening cross-examination on handling gaps, which can persuade the fact-finder to discount the evidence even though the judge still let it in.
Who decides admissibility if weight is a jury question?+
The trial judge decides admissibility as a threshold legal question, typically applying rules on relevance, authentication, and reliability, before the jury ever hears the evidence and assesses how much to believe it.
Can evidence with very low weight still support a conviction?+
Alone it usually cannot; convictions typically rest on the combined weight of multiple pieces of evidence, so a single weak item is assessed in the context of everything else the fact-finder has before it, not in isolation.
Related terms
- Admissibility
- Whether a piece of evidence is permitted to be placed before the fact-finder at all. Admissibility is a threshold question, decided by...
- Adversarial System
- A legal model in which two opposing parties (prosecution and defence, or claimant and defendant) present competing cases to a neutral decision-maker....
- Authentication
- The process of establishing that a document is what it purports to be. Under the US FRE Rule 901, the proponent must...
- Burden of Proof
- The obligation to prove a fact or claim. In criminal law the prosecution typically bears the burden; in civil law the claimant...
- Chain of Custody
- The documented chronological record of who collected, handled, transferred, and examined a piece of evidence. For digital evidence, chain of custody includes...
- Continuity of Exhibit
- The principle, applied in English and Welsh courts and reflected in PACE Code B, that an exhibit must be shown to have...
- Fact-Finder
- The person or body whose job is to determine what the facts are: a jury in common-law criminal trials, a judge sitting...
- Inquisitorial System
- A model of legal proceedings, common in civil-law countries such as France and Germany, in which the court takes an active role...
- Probative Value
- The strength of the evidence's tendency to prove or disprove a fact in issue. High probative value means the evidence substantially changes...
- Standard of Proof
- The level of certainty required to discharge the burden. Common criminal standard: beyond reasonable doubt. Common civil standard: balance of probabilities (more...
Explained in these topics
- Chain of Custody as a Legal Construct
- Forensic Science and the Law: An IntroductionHow much a piece of evidence contributes to the fact-finder's conclusion, as distinct from admissibility (whether it is allowed in at all). Admissibility is a...