A public defender shall represent any indigent person who is:
(1) Detained by a law enforcement officer without charge or judicial process;
(2) Arrested or charged with having committed a crime or of being a juvenile delinquent;
(3) Detained under a conviction of a crime, juvenile delinquency, or mental illness; or
(4) Otherwise an indigent person entitled to representation by law, to the same extent as a person having his or her own counsel, and with the necessary services and facilities of representation, including investigation and other preparation, authorized or approved by a court.