Death Penalty

Just read this article about a Texas inmate who killed himself shortly before he was scheduled to be killed by the state. I'm not sure why it's such a tragedy that he died a few hours before schedule, but it is, and it horrifies me in many ways. I've never known quite what to think about the death penalty. This inmate claimed his innocence, so is the state killing an innocent man? But on the other hand, it is right to keep alive those who have killed and ruined the lives of others? And to have taxpayers bear the brunt for it? The man was my age, I can't even imagine what his life must have been like to put him in such circumstances.