It likely depends upon the type of crime you are trying to prevent. If you are trying to prevent crimes where the perpetrator assumes there will be no witnesses

It likely depends upon the type of crime you are trying to prevent. If you are trying to prevent crimes where the perpetrator assumes there will be no witnesses, then I can see how surveilance could[1] be effective. If you are talking about a mass shooting, a crime where the perpetrator must assume there will be witness and they will be caught (short of suicide, which seems to be common in these scenarios, then it is hard to see how surveilance will be effective. [1] I say could because it probably involves the mental state of the person commiting the crime.