You having your friend murdered does not validate your opinion, nor does it entitle you to take the life of someone else out of anger, but whatever.

Murdering murderers is wrong because it is utterly pointless. Just like murdering innocent people is wrong. It takes a persons life away without providing any benefits. It does not make the grief of losing a loved one go away, and it is far mentally healthier to the victim's family to try and let go of their anger instead of entertaining it.

Countries without the death penalty statistically have either the same or lesser of a crime rate than the U.S. And while I agree with you that violent criminals should not be given luxury prison lives, they should be treated like human beings because torturing them does NOTHING but create a second victim.

You can argue killing murderers saves money, but I'd like to think we live in a world where the life of someone is considered to be more valuable than the $15 a year the average taxpayer has to pay for the current amount of inmates incarcerated in prison for life without parole. And yes, the victim's family should still pay for the lives of criminals because the idea of paying for someone to live is not going to magically make the grief of losing a loved one 100 times more intense.