The High Cost of Death Penalty

This article tells on why the death penalty is expensive. They give an example on capital punishment in California, where over 3,500 people have been sentenced to death by the state and not one of them have been released, except those very few people who proved their innocence. The author of the article believes that the death penalty should be replaced with life in prison without parole.
http://www.deathpenalty.org/article.php?id=42