In Japan, an officer may arrest a person they believe may have committed a crime. They can detain the person for up to 48 hours. The police are required to inform the person why they were arrested. During the 48 hour period, the person may be brought before a prosecutor if the police have enough evidence. If the prosecutor believes the evidence is enough, they request a warrant of detention before a judge within 24 hours. The defendant appears before the judge when the warrant is requested. The case may be dropped for lack of evidence either before the prosecutor or before the judge.