Those who are addicted chances of they turning to criminal increases because in addiction every time you can only think is gambling and to gamble you require money. You cannot win every time from gambling and thus results in the losses and to get more money people start doing crime.
This is 100% truth, it's like drug addiction precisely or almost any addiction. The fact that they think they can prey on casinos customers is because of that and also because they take some sort of have fun without limits mindset which often leads people around there to use their products or services(Drugs, prostitutes).
Are criminals wrong? They definitely know what they are a doing. Even if it's not the casinos fault if they are not linked with them it certainly is a consequence of having one nearby.