Since we cannot kill him as he killed his victim because it would be "cruel and inhumane". I have a plan.
A lottery for volunteers. Any state resident, registered voters only can buy a $1 dollar ticket for a chance to be one of the seven members of the firing squad. Drawing will be announced in one month, on Saturday night on live TV.
The seven winners are invited for a weekend training session at the prison chosen for the execution. They are given Iron sighted M1903A3, C-stock ex-military rifles and GI issued 30-06 ammunition and they have a 40 round sight-in session and three rehearsals at a dummy target followed by a BBQ and celebration with the guards.
Two weeks later and at 7pm on live TV, the scumbag is marched into the courtyard and sat in a chair on front of a heavy sandbag wall. He is given a moment to speak and a chance for a prayer and then shot from 25yds away by seven people with high powered rifles. A coup-de-grace is administered if required by the Captain of the Guards or a suitable person.
You are returned to your regular scheduled programming.
The money from the lottery is used for rifles, ammo, T-shirts commemorating the event, range upkeep, stipends for the shooters and attending guards, a modest pine box for the scumbag and $10 dollars in flowers for his funeral and 25% is returned to the victims family to help ease their pain.