A crime, which is a violation of the law that carries either a jail sentence or a fine as the penalty, is a serious matter for the person charged. Because the penalty is so severe, the requirements for the state or government to prove a person committed a crime are strict. Most crimes require proof that the person committed the act with intent or knowledge. However, crimes such as drunk driving usually only require proof the person was operating a vehicle over the legal limit. Understanding the elements of what constitutes a particular crime are essential to presenting an effective defense.