system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: If a prisoner is sentenced to death in the US, why aren't they killed on the spot? (Or within the next couple of days)

I've heard how keeping a prisoner on death row costs more than life in prison. Why aren't they just killed right away to save costs?
gpt
They are given every legal benefit of the doubt to appeal their conviction before they are executed.  It seems wise to err on the side of caution when you are going to do something you can't fix if you happen to be wrong.