The OP seems to imply that somehow gambling increases illegal activities and gives the example of prostitution and the consumption of drugs, but what gambling does at best is to attract those kind of people because they know that the people inside the casino have money to spare, but gambling in itself does not increase those activities, those activities will happen anyway, however there are some crimes that could go up due to the influence of gambling, for example those that are addicted to gambling will probably steal money to try to feed their addiction.