Jury Instructions - United States

United States

Under the American judicial system, juries are often the trier of fact when they serve in a trial. In other words, it is their job to sort through disputed accounts presented in evidence. The judge decides questions of law, meaning he or she decides how the law applies to a given set of facts. The jury instructions provide something of a flow chart on what verdict jurors should deliver based on what they determine to be true. Put another way, "If you believe A (set of facts), you must find X (verdict). If you believe B (set of facts), you must find Y (verdict)." Jury instructions can also serve an important role in guiding the jury how to consider certain evidence.

Forty-eight states (Texas and West Virginia are the exceptions) have a model set of instructions, usually called "pattern jury instructions", which provide the framework for the charge to the jury; sometimes, only names and circumstances have to be filled in for a particular case. Often they are much more complex, although certain elements frequently recur. For instance, if a criminal defendant chooses not to testify, the jury will be often be instructed not to draw any negative conclusions from that decision. Many jurisdictions are now instructing jurors not to communicate about the case through social networking services like Facebook and Twitter.

Several studies have discovered that subjects who received no jury instructions comprehended the law better than subjects who received pattern instructions. Jurors retain low comprehension of the most fundamental aspects of their roles. For instance, scholarly studies and anecdotal evidence suggest that jurors conflate reasonable doubt with the civil standard of preponderance of the evidence.

In one study, citizens willing to impose the death penalty were presented in 2 experiments with 4 sets of instructions (i.e., baseline instructions, instructions used at trial, instructions revised according to Eighth Amendment to the U.S. Constitution holdings, and model instructions written in nontechnical language). Results demonstrated high confusion with the trial instructions, little improvement with revised instructions, significant but case-specific improvements with model instructions, and a strong relationship between miscomprehension and willingness to impose death.

In California, jury instructions were simplified to make them easier for jurors to understand. The courts moved cautiously because, although verdicts are rarely overturned due to jury instructions in civil court, this is not the case in criminal court. For example, the old instructions on burden of proof in civil cases read:

Preponderance of the evidence means evidence that has more convincing force than that opposed to it. If the evidence is so evenly balanced that you are unable to say that the evidence on either side of an issue preponderates, your finding on that issue must be against the party who had the burden of proving it.

The new instructions read:

When I tell you that a party must prove something, I mean that the party must persuade you, by the evidence presented in court, that what he or she is trying to prove is more likely to be true than not true. This is sometimes referred to as 'the burden of proof.'