CNN:

An Oklahoma death row inmate received a drug commonly used to euthanize animals Thursday because of a nationwide shortage of sodium thiopental, the drug usually used as the sedative in its three-drug execution cocktail.
John David Duty was convicted and sentenced to die for strangling his 22-year-old cellmate, Curtis Wise, with shoe laces in 2001. At the time, he was serving three life sentences for rape, robbery and shooting with intent to kill from a 1978 conviction.
The drug used to kill dog animals successfully (and unsurprisingly) killed the human animal. More important is this: The human animal repented before being executed; meaning, he had a moment of grace:
"To the family of [the man I killed with my shoe laces], I'd like to make my apology. I hope one day you will be able to forgive me, not for my sake but for your own. My family and friends are here too. Thank you. You've all been a blessing. Thank you. Lord Jesus, I am ready to go home..."
As Michel Foucault and William Flesch point out in their books, people have respect for murderers who repent or do not repent at all. The murderers who become weak in the legs and beg and cry for mercy get no respect from the public.