Along the same lines as the above posts, there is the argument for the legalization of marijuana. Taking the profit out of the trafficking of marijuana through legislation could easily have the same effect as eliminating Prohibition did. In fact, some states have decriminalized the sale of medical marijuana already.
The decriminalization of the sale of marijuana would have several positive effects. It would definitely reduce many of the criminal activities in U.S. border states that reach far into their territory. For instance, in the May 10, 2010 edition of Newsweek in an article about the dilemmas of Arizona, Eve Conant writes,
An hour later they [sheriff's deputies] raided a McMansion adorned with hunting trophies and Scarface posters; a white SUV jammed with 300 pounds of marijuana was parked out front. (Sixty percent of all the marijuana that reaches the U.S. transits Arizona.) Against the house was in a high-end development, nowhere near the border.
Another improvement needed in the criminal justice system is the fact that there is no adequate sentencing for pedophiles. Studies have demonstrated that there is virtually no rehabilitation for pedophiles, who repeatedly offend. After having served time in prison and they are released, they commit their crimes again; in addition, as they realize that their chances of getting away with their crime are increased, they often, then, murder their victims.