Section 169 Cr.P.C. deals with a situation an Accused could be released for lack of evidence.

The Officer Incharge of a Police Station has reasons to believe that after conducting investigation over the person’s alleged involvement into an offence he found no sufficient evidence so to forward the Accused to the concerned Magistrate then the Police Officer can release [if arrested] the Accused on executing a bond with or without sureties and instruct the Accused to appear, in the Court when required and upon the Court took cognizance of the offence on a Chargesheet, to face the trial.