No, I do not believe "stop and frisk" policies contribute to actual reductions in crime. In theory, any busts made by "stop and frisk" methods would actually add to the number of crimes recorded (more busts, more documented crimes). "Stop and Frisk" policies are in no way a deterant to crime commissions.
The problem with stop and frisk is that it seems drastic and heavy handed. And it is. It is a draconian way of addressing crime. But, with that said, there is evidence showing it works. Crime rates plummeted under this stop and frisk law. Bad law, but effective. Ethical problem.
The law enforcement policy of "Stop and Frisk" does actually reduce crime because it deters other people from wanting to be caught carrying something illegal, be it a weapon or a drug. In addition, a person being stopped and frisked that is caught carrying can be deterred from committing a crime as well.
No, the law enforcement policy of Stop and Frisk does not actually reduce crime, but it is done to keep officers safe. When an officer conducts an investigation, it is helpful to know whether the people he is speaking to have weapons on them. Stop and Frisk only comes into play when law enforcement detains someone for good cause.
I do not believe the law enforcement policy, "Stop and Frisk," does anything to actually reduce crime. If anything I think the policy is a severe breech of privacy that stops innocent citizens on the street for no know reason. I believe officers should us probably cause, otherwise it could slowly turn into a policy of harassment.