Criminal Charges and Bail
Criminal proceedings are started by a formal allegation (charge) by, say, a police officer, that a person did something which is forbidden by law. A suspect cannot be dealt with until they have been formally confronted with the allegation.
Police have the power to grant bail to a person who has been arrested with or without a warrant. The power to grant bail is at the discretion of the police. Police can release persons from custody provided that the person has not been arrested on a warrant, and if it is in the interests of justice to do so. There is a section dedicated to Bail.