A jury is a sworn body of people convened to render an impartialverdict (a finding of fact on a question) officially submitted to them by a court, or to set a penalty or judgment. Modern juries tend to be found in courts to ascertain the guilt or lack thereof in a crime. In Anglophone jurisdictions, the verdict may be guilty or not guilty (not proven; a verdict of acquittal, based on the state's failure to prove guilt rather than any proof of innocence, is also available in Scotland). The old institution of grand juries still exists in some places, particularly the United States, to investigate whether enough evidence of a crime exists to bring someone to trial.
The modern criminal court jury arrangement has evolved out of the medieval juries in England. Members were supposed to inform themselves of crimes and then of the details of the crimes. Their function was therefore closer to that of a grand jury than that of a jury in a trial.