Why do people who have everything become criminals and risk everything?

I have these 2 wealthy neigbhors who are brothers who are both doctors who both live together. They easily make over $400,000 each with their career. They live together in a $2.5 million waterfront mansion with a huge yaght on their back docks and a few bentley's in the driveway. They are party doctors who were living a great life, they even have a politician in their back pockets. They're all friends. That politician gets them into a game of corruption, bribary and money laundering 10 years ago and recently the 3 of them were caught by the feds. Now facing a slew of charges. I mean why would 2 wealthy people as is who have everything want to get involved in criminal activities to get more money when they didn't need that extra money? Would you not be satisfied with $400,000 a year, $2.5 million mansion, bentley's, dream vacations, and a yaght, would you really need to start doing illegal things to make more money? What drives people to risk everything when they already have everything?