I honestly used to be for it when I was younger. I am not for it now. The only thing that I don’t like about giving them a cozy spot in the cell forever is the tax burden that is incurred on the people. However if I am judged according to how I judge others, then I choose to show mercy and forgiveness to my enemies and let God judge them. I pray for my enemies, not execute them.
I know that they stoned people to death for various crimes in the OT, but they also didn’t really have the technology at the time to house dangerous murderers and the like. Escape proof, steel prisons, capable of housing an inmate for life wasn’t that common back then. It’s not like you could just let a murderer or rapist go free in your village and trust that he would never come back. However, if I do have the ability to show mercy, I will.
When Jesus was being murdered on the cross, he forgave those murderers. I choose to follow his example.