I agree, but for a fitting punishment, I think you have to understand the how and why of the crime that was committed. The motive and method tells me a lot about what kind of danger the person is to society.
In Iraq, a vehicle full of booby trapped children's toys was found recently. I'd be comfortable in giving out the death penalty to whoever built them, whoever was going to distribute them, and anyone that knew about them and said nothing. Still, I wouldn't want to execute a woman that shot a cheating husband after catching him in the act. Murder is wrong, but the details should dictate how severe the punishment.
(Denny Crane: "I Don't Want To Socialize With A Pinko Liberal Democrat Commie.Say What You Like About Republicans. We Stick To Our Convictions. Even When We Know We're Dead Wrong.")