The intent of three-strikes (and even two-strikes) laws is to incapacitate selected violent offenders for very long terms-25 years or even life. They have no specific deterrent effect if those confined will never be released, but their general deterrent effect could, in theory, be substantial." In this regard, mandatory sentencing guidelines appear to be good policy when it comes to deterring potential criminals from committing crimes, but that is not necessarily the case if a criminal has already be incapacitated. It is more of a case of setting an example for others.
There are pros and cons to mandatory sentencing, but they seem to vary upon different factors such as location in the country. First of all, let us take a look at the possession of handguns. The case study mentions, for example, possession of unlicensed handguns in Massachusetts and how the law has been effective there. The same law, however, has not been effective in Michigan and Florida. However, it has bee effective against homicide in Detroit, Jacksonville, Tampa, Miami, Philadelphia and Pittsburgh, though it has not been effective against other types of violent crimes, such as sexual offenses (Case Study 3.2 2008).