Trust is a basis for functioning of human society. It exist in some form if a community/country has to thrive. Data Security scientists are still working on defining trust in the terms of mathematical models for web, open systems etc. but haven't reached far.
Trust is like two straws in different directions between different entities keeping them in sync. Hence works best when the entities are at the same conceptual/perception/physical level. Is this what makes the corrupt people trust only corrupt? In some countries such as India for authorizations and public services or any other official purpose, only people working for the government are trusted and have approval authorizations despite knowing that they would probably be the most corrupt one!! Why dont the government procedures allow for an independent trust checking setup for measuring the corruption in government. I guess hopefully that would be covered by the so much touted Lokpal Bill.
But hey catch-22, who checks the sanctity, credence and faith of the investigators itself!! Since people themselves can't be trusted to do this job as they are the one who sent the corrupts to power in the first place and you dont want the corrupt to check their own trust. Could we call upon the God to do that? HE should be willing to take up this meagre task for the benefit of the society which He loves most as claimed by the culture !!!