When an investigation progresses to the point that the police have probable cause and there is a reasonable belief that a person has committed a crime, they may make an arrest. An important part of this phase is the determination of what offense or offenses have been committed. Some conduct can be charged in a variety of ways. For example, depending on the facts, a Driving Under the Influence case can be charged as either a misdemeanor violation of the state law or of a city or village’s municipal code, or prosecuted as a felony offense under state law. If the police officer determines that the matter should be charged as a misdemeanor violation of state law, then the case will be prosecuted by the State’s Attorney’s Office. This decision is usually based on the general orders adopted by a particular police department.
On the other hand, if the police officer believes that felony charges may be appropriate, he or she must contact an on-call Assistant State’s Attorney who will review the case and make the ultimate decision on whether to file a felony charge. If the Assistant State’s Attorney determines that a felony is not warranted, the police can still file misdemeanor charges.