Magistrate's duty to hear prosecution and collect evidence; may, on application, summon witnesses or compel documents. When a warrant-case is instituted otherwise than on a police report and the accused appears or is brought before a Magistrate, the Magistrate shall proceed to hear the prosecution and take all such evidence as may be produced in support of the prosecution; and the Magistrate may, on the application of the prosecution, issue a summons to any of its witnesses directing him to attend or to produce any document or other thing.