Well a lot of crimes should be punishable by death but it's not gonna happen.
That's why very few individuals, lifetime prison doesn't shake them by ounce when they know they would be left alive in cage. The matter is the chances of getting out prison is what most count on.
That's why citizens in Saudi Arabia treasure not only their lives, but even their enemies. The last thing a native or foreign would think about is killing. Sure, there are very few individuals selling out their lives and would kill without second thought.
There are times when anger gets the best of me, I imagine if I killed someone, I dunno what's next. What kind sanity my mind could resist. Knowing I took someone's life, the idea of being beheaded scares the shit of me. I would pussy out. I wouldn't be able to kill, unless a great force of anger pushes me to kill someone over worthless personal matter that doesn't deserve losing my life for it.
It would be quite a struggle of mentality. Let's even say someone killed one of my family. If I killed him due to revenge for the death of one of my family, even though the murderer is one way or the other is dead by me or by government, I would even receive death penalty too, because in my country no one allowed to take the law by his hand. Vigilantism has no room here in Saudi Arabia.