The Oklahoma Court of Criminal Appeals has denied a white former Oklahoma reserve deputy's request to reconsider his conviction for the fatal shooting of an unarmed black man.
The court on rejected a request for a rehearing in the appeal of 76-year-old Robert Bates.
The court last month upheld his second-degree manslaughter conviction in the April 2015 fatal shooting of 44-year-old Eric Harris.
Bates said he mistook his handgun for his stun gun when Harris was shot during an undercover investigation. Bates was paroled in October after serving just more than 16 months of a four-year prison sentence.
In a decision handed down on Wednesday, the appeals court says "no reasonable person" would believe that the use of deadly force was justified in the situation in which Bates shot Harris.