Good Or bad

Maoists or terrorists obviously try to justify their cause but nothing is justified with the lives of many.But are the police or other inquiring bodies justified to catch hold of innocent people in the name of crime.How do we differentiate actual criminals with real innocent people.The question of who is good or who is bad will always be unanswered,till then thousand of innocent people will be tortured in name of justice.what pains me the most is the incapability of the inquiring bodies to catch the actual culprit.Hope the police & judicial system understand the circumstances of an innocent associated with the said crime.