Prejudicial Effect
Definition
The risk that evidence will influence a fact-finder's decision through emotion, bias, or confusion rather than through rational inference. Courts balance prejudicial effect against probative value in admissibility rulings.
- Nature of risk
- Emotional, biasing, or confusing influence on fact-finder
- Balanced against
- Probative value
- Decided by
- The court, at admissibility stage
- Applies to
- Evidence generally, including graphic or expert testimony
Common questions
How does a court decide whether prejudicial effect outweighs probative value?+
The judge weighs how much the evidence genuinely helps prove a fact in issue against the risk it will sway the fact-finder for reasons unrelated to that fact, such as shock or sympathy, and excludes the evidence when that risk substantially outweighs its probative contribution.
Why is graphic forensic evidence, such as autopsy photographs, often subject to this balancing test?+
Such evidence can be highly probative in establishing cause or manner of injury, but its emotional impact also risks inflaming a jury beyond what the facts alone would justify, so courts often require redaction, selection of less graphic images, or expert summary in place of the most extreme material.
Related terms
- Defence Fallacy
- The converse error of inflating the importance of the RMP by arguing that, because many people in the population share the profile,...
- Likelihood Ratio (LR)
- The ratio of two conditional probabilities: the probability of the observed evidence given the prosecution's hypothesis (same source), divided by the probability...
- 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...
- Prosecutor's Fallacy
- The error of treating the RMP (or its reciprocal) as the probability that the defendant is innocent, or as the probability that...
- Relevance
- The logical quality of evidence that makes a fact in dispute more or less probable. Under FRE Rule 401, evidence is relevant...