If laws against guns will stop murder and violence, why do laws against murder and violence not stop such?

Pratt on Texas listener Steven recommended “remedy” as Word of the Day, using the feature to do so at PrattonTexas.com, and provided this usage:

Yet again we have another mass murder at a school, and the gun control advocates are out within minutes, salivating over another opportunity to push their agenda; never mind the ghoulish nature to do so before mourning can even begin.

What such advocates seek to bring to life is a fantasy world where the law and the State is so powerful that it can prevent crime by simply enacting law.

They and many others, fail to recognize the purpose of the law: to provide a mechanism for a remedy of a grievance and to do so in an orderly, civilized manner. The law CANNOT prevent evil from making its appearances on earth.

Steven is on to one of the great problems in our society. The idea that anytime something horrible, or just unpleasant, affects us, we should run to government to “to do something” which generally means passing yet another in an unknowably long list of laws.

Laws are important and civil law requires that people generally respect and abide by those laws for them to work. Inherent in criminal law is the idea that there will be those who ignore law and thus criminal law is focused more upon obtaining some type of societal justice after a crime is committed.

Why do some think that a law making the possession of a firearm illegal will stop violence and murder?

Do those same people believe the laws we already have against murder and violence stop such from happening?