1-304.   When Policemen to Make Arrests.
   Unless otherwise authorized or directed in this code or other applicable law, an arrest of the person shall be make by a policeman in the following cases:
   (1)   Whenever he is in possession of a warrant for the arrest of the person.
   (2)   Whenever an offense is committed or a breach of the peace is threatened in the officer's presence by the person.
   (3)   Whenever a felony has in fact been committed and the officer has reasonable cause to believe the person has committed it.
(For provisions relating to traffic citations, etc., see Title 9, Chapter 6, in this code).