The little white-collar executive-type crook these days can often succeed in picturing himself as a "gentleman." He wouldn't dream of associating with thugs: He steals in a genteel way and wouldn't harm a fly. Of course, if he should happen to bankrupt his kind employer's business and force his sweet employer's wife to find work so their son not be deprived of a college education, why that's no skin off his back! No He is intent on his personal needs. The money is there to take, isn't it? It's only money, isn't it?
You really cannot expect to conduct any size business for any length of time without brushing up against some inside crook.
Are you afraid to act on that assumption? Afraid that the adoption of realistic protective methods would irritate your honest employees? Do not be misled by your own ignorance of such situations. Your best employees at this very moment may be shivering in their boots, afraid of the crook in their midst who intimidates them, wondering when you are going to be businessman enough to stand up and stop the stealing! Do so; If you don't , you will only teach them that stealing is not punished, and encourage some of them to go and do likewise.
It is your responsibility to keep a constant guard on the resources of the business you run, the same goes for your personal finance. Even if you are insured against loss you cannot expect the insurance company to keep that guard for you. They can only help you by making suggestions of techniques. They will pay for proven loss, certainly. But experts estimate that much more is lost that is never discovered.