I can see why the death penalty is rarely used, it's a shame really where this man could be innocent whereas certainly guilty people are put in for life, etc. :<
Its made to work out for everyone. If you really did commit the crime, and know you are probably going to get caught for it, it makes since to take the plead. Since many guilty people plead "guilty", the courts are supposed to have less stress and the accused gets off with a lighter sentence. This, of course, doesn't work off so well when actual innocent people plead innocent, taking the harsher sentence.
But it really doesn't matter what you or I thinks on the subject, just what the jury thinks. Its like the Casey B. Anthony trial (Hopefully I got the correct name.), except in reverse. Everyone thought Anthony was guilty, maybe even the jury, but they didn't have "beyond a reasonably doubt" needed for the death penalty. Here, some seem to think he was innocent, but the jury had the "beyond a reasonably doubt" so he was convicted. But, once again, he had a ton of witnesses against him, with half that he would have been convicted.