A question of law is an issue which comes up before, during, or after a trial which pertains to interpretation of the law. Questions of law are decided by a judge, who weighs the available information, considers his or her knowledge of the law, and issues a ruling on the matter. Judges also determine whether or not a question brought up in court is a question of law or a question of fact, as questions of fact are decided by the jury, not the judge, in jury trials.
By contrast, a question of fact concerns the actual factual events which occurred. In trials where a jury is not present, the judge rules on both questions of law and fact, but in jury trials, only the jury can decide on the facts. It is the responsibility of the judge to make sure that the law is applied fairly and appropriately to the case, allowing the determination of facts to be made by the jury.
For example, in a murder trial, the question: “Did the defendant kill the deceased?” is a question of fact. It must be decided by the jury on the basis of the available information. By contrast, “If someone buys a gun, plans to kill a person, and shoots someone with it, is it first degree murder?” is a question of law. Questions of law can be raised by either party during the trial and they require legal expertise to answer.
When cases are appealed, it is most often questions of law which are discussed in the appeal. Unless there were drastic problems with the way the facts were presented at the initial trial or critical information was missing, the determination of the facts is considered valid. What may be questioned in the appeal is whether or not the questions of law were properly settled. Sometimes a question of law depends heavily on the discretion of the judge and another judge may rule that the first judge was actually incorrect.
When a judge makes a decision about a matter of law, the judge may issue a formal written opinion. This is especially important when the judge is making a decision which may be controversial, or is interpreting a law in a new way. This written opinion on a question of law can be referenced by other judges when they make determinations about matters of law, and such legal decisions become part of jurisprudence.