An acquaintance of mine is a US Attorney. We got talking “crime and criminals” once and his comment stuck with me: essentially, all criminals have two full-time jobs. First, you have to advance your criminal enterprise. But second you have to not get caught. And just like your typical salaryman, criminals have off days, get lazy and phone it in, or get cocky and think they’re pulling one over on the boss. And all the while he has dozens of highly paid investigators with one job: to catch people slipping.
Most importantly, while the criminal has to be perfect all the time, his investigators just have to be right just once.