forgiveness is one thing, Making sure these folks never kill again is a responsibility.
That is one consideration that tips me toward the death penalty. First, very few prisoners get a life sentence; second, very few who "get" a life sentence actually serve it until death: somehow they manage appeals, resentencing, parole, court-ordered releases to alleviate overcrowding, or even escape; third, even in prison, they are not "out of society," since prison is a society itself, and these guys assault, rape, injure, and kill other convicts, as well as correctional officers, tutors, medical personnel, and other members of the prison "society."
I read somewhere --- and how I wish I could find the source! It was on the Internet, but I've never been able to find it again --- that an average of 500 people are murdered every year, *BY* someone who was already in the past convicted for a previous murder, in California alone!!
The "criminal justice" system is not carrying out is moral mandate. Executions for this kind of horrendous crime should be swift and certain.
And yes, you can sincerely forgive a man who has committed a crime, and execute him.