The gist of the case:
Richard Glossip is scheduled for execution in Oklahoma on January 29, 2015. He was accused of commissioning the murder of his boss. The murderer, Justin Sneed, testified against him in exchange for a plea deal.
Richard however maintains his innocence and has been on hunger strike to protest his execution.
The most damning and crucial evidence against Richard is the testimony of the killer, Justin Sneed, who claims that Richard offered money to Justin to kill Richard’s boss. Sneed testified in exchange for a plea deal that spared him the death penalty. This move gave Justin, the actual killer, life without parole while Richard is on death row.
So the actual killer avoided death row by implicating Richard.
I have not investigated the facts for myself. But it is believed that Richard Glossip is innocent.
It makes no difference to me whether he is or not, because I don't think we should eliminate human life if we can adequately protect society without killing.
More details here.