The police investigate a suspect, and present the evidence to the District Attorney (DA). If the DA thinks there is enough proof, they will present it before a grand jury, who will decide if there is probable cause to support the criminal charges. If they decide to indict, the case will go to court, and be tried by a regular jury. A judge presides the trial, a prosecutor accuses the defendant, and a defense lawyer is responsible for his or her defense. If the defendant does not have enough money to pay for a lawyer, he is provided the services of a public defender.