Research tools?

Ok, I'm looking for any advice on research tools for investigation, legal and available on the internet. Essentially I would like to be able to search someones academic history, criminal record etc, without having to pay for it.

To put this into context; in the place where I work, one of our employees is currently under investigation for unauthorized absence. However, after conversations, I get the distinct impression that he is lying about his academic achievements and possibly about his criminal record. He makes everyone "uncomfortable" and there is a general feeling he may be prone to violence. He has also admitted to using aliases.

Any help greatly appreciated.