There is a difference between justice and mercy, but they are not enemies, they go hand in hand. Justice is a rightful punishment to a crime, mercy involves forgiveness. Whether one believes in the death penalty or not, the point of the sentence, whether it is jail time or death, is to take that person out of a situation where they can hurt innocent people, the point is not revenge or retribution. The actions you have suggested sound like medieval torture, and are only implemented out of spite, and hate. Hate does not solve anything, hate does not bring back someone from the dead. When resorting to these acts of hate, you are stooping down to the criminals level, the criminal has won. You have committed an unjust act out of hate just like the murderer did. Now you are no better than the criminal. In addition, the methods that you are suggesting would be unconstitutional as they are considered cruel and unusual punishment. Though many murderers obviously have some huge mental issues, it is not impossible for murderers to regret what they did and want to become better people. Case in point, around 1902, an 18 year old named Alessandro raped and killed a 12 year old girl names Maria. On her deathbed, she forgave him. Alessandro was sentenced to 30 years in prison. The first thing he did when he got out was go beg her mother for forgiveness. Maria was canonized in 1950, and a 66 year old Alessandro came to witness it, and wept. Just remember, hate will never solve anything and will only bring about more crime and murder. Murder is wrong, there is no doubt about that and it must be punished. That is justice. But promoting a culture of hate and vengeance will only lead to more hate and vengeance. That is where mercy needs to come in.