A prosecutor is a lawyer who works for a state or government organization and is responsible for initiating legal proceedings and then proving in court that the suspect committed the crime of which he or she is accused. The opposite of a prosecutor is a defense lawyer. In this TV crime drama, the prosecutor is the one trying to put the bad guy in jail, and the defense attorney is the one trying to prove that the guy really isn`t a bad guy. Britannica.com: Encyclopedia article on the prosecutor In a TV crime thriller or in real courts, the prosecutor is the person who files criminal charges against a suspect.