Legal costs of getting them sentenced to death. Apparently it takes $1.5-2 million to pay for the legal proceedings necessary to go beyond life in prison, while room & board & etc for life in prison costs about $500k.
That makes it really easy to be against the death penalty.
I would like to think that the decision of whether to execute people would not be based on financial concerns.
Oh. That's ridiculous. I feel like that's a sign of a problem elsewhere in the system.
It's the cost of appeals. Whether you consider that a problem probably comes down to political leanings (discussions of which are best avoided on HN).