Rule 403 of the Federal Rules of Evidence and the Massachusetts Guide to Evidence empowers judges to exclude evidence, which may pass the relevancy test (a rule of evidence explored in one of our previous blogs), but nevertheless unfairly biases jurors towards one side or the other, confuses them, or simply wastes the court’s time by raising redundant issues. Unfairly or unduly are the operative words; all evidence is prejudicial but the question in this instance is it unduly or unfairly prejudicial.
Considerations are often based upon: whether the proffered evidence triggers strong emotional reactions from the jurors such they cannot fairly decide the issue before them, whether the evidence is particularly important to establishing elements of the case, whether there is some alternative way to have the evidence admitted, and finally, whether the jury can be given limiting instructions as to how the evidence may be used by them.
The above is a balancing act, which the judge employs. It is the judge’s determination as to whether the probative value is “substantially outweighed” by unfairness, confusion or undue delay. You will notice that the Federal Rules of the Massachusetts Guide insert the additional consideration of substantial, something that not all codified rules of evidence in other jurisdictions require. Again, it is worth keeping in mind that all evidence is prejudicial and that is not the concern. The concern is whether the admitted evidence will lead to unfairness.