My experience with friends in law enforcement is that what defines the majority criminals is a lack of understanding of risk. That lack creates a strong sense of "I know how to get away with this."

I remember a story of a guy being busted who ran a business, bought his $500k house in cash, his half dozen trucks in cash, and yet paid almost nothing in taxes. The thought was, "I'll under-report my income, and pay everything all in cash so they can't trace anything!" Except for the fact that transactions over $10K get reported to the IRS, not to mention all of the property to various agencies which circle back to the IRS.

People who have a least a clue what could go wrong tend to also realize they probably aren't seeing other ways for it go wrong, as well.