Looks like this has been put on hold for a while. Now, I'm not familiar with this case but one particular thing struck me as odd, from the article:
Banks shot Whitehead "for the hell of it" after a night of drinking, according to testimony Banks gave at his trial.

Now, if you admit to the crime, at your trial, doesn't that make you guilty? What else is there to discuss?

Supreme Court issues stay posponing Texas' 300th episode..errr..execution