You are now President. You walked into office with extremely high inmate and crime percentages. Thinking they know human instinct because they watched some high budget movies, Congress is now asking you to address these issues, and they offer you two choices.
A) Purge. Essentially the same deal as the movie where for one night a year, all crime including murder is legal for 12 hours. Congress believes that this can solve crime rates because people can release their inner beasts for just one night, and will therefore be "cleansed" for a whole year, leading to lower crime rates since their bloodlust should be sated for a whole year.
Or
B) Gladiatorial combat. Basically you turn the prison system into one big orgy of fighting, but only for perpetrators of serious crimes like murder, rape, etc. They all fight for their right to survive while entertaining the masses on Pay Per View, and there can be a volunteer system for people who just want to go in and fight.