Why would a person who was able to pass background check and has security expertise - risk his safe life and good income by dealing with criminal gangs? Yes, i

Why would a person who was able to pass background check and has security expertise - risk his safe life and good income by dealing with criminal gangs? Yes, it's possible, but as an exception, not as a rule. Criminal activity would never stop completely, but not because it's impossible to beat criminals, but because as soon as crime goes down - people and businesses start doing more risky activities, trust more and check less.