In most cases, the police require a warrant in order to arrest someone. To obtain a warrant the police, or public prosecutor, must present evidence to a judge who then will issue a warrant if convinced that there is probable cause to suspect that the target of the warrant has committed a crime. The lengthy process of obtaining a warrant protects the public from baseless arrests but there are two main exceptions. First, warrants need not be obtained for flagrant offenders who are caught in the commission of a crime or immediately thereafter. Second, in cases of great urgency where a serious crime has been committed, public prosecutors may make a warrantless arrest of a suspect as long as they explain the basis for the arrest to the suspect.
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