First-degree murder of a peace officer

Read the prompt, review the case, and then decide whether enough evidence exists to meet the burden of proof.
The defendant was convicted of attempted first-degree murder of a peace officer when he shot a sheriff. The defendant contended that he did not know the victim was a peace officer. The sheriff was in a vehicle with a whip antenna, was armed, and was well known as a sheriff in Angola Prison, where the defendant was incarcerated previous to the shooting incident. However, the sheriff was in an unmarked car with the red light covered, out of uniform, and his badge was obscured. Is this sufficient evidence to prove beyond a reasonable doubt that the defendant knew the victim was a peace officer? Read Donahue v. Burl Cain, 231 F.3d 1000 (2000). The case is available at this link: http://openjurist.org/231/f3d/1000/larry-donahue-v-burl-cainLinks to an external site.