A former Alabama sheriff's deputy has been haunted by a single gunshot for more than five decades.

Quinnie Donald shot and killed a black man in 1964 outside a house known for selling illegal booze. If the same events played out today, the death of Frank Andrews might have become a flashpoint in the national debate about police use of force and minority rights.

Instead, the white deputy spent 50-plus years second-guessing his actions and waiting to find out whether he would be prosecuted.

That uncertainty ended only weeks ago, when Donald learned that the FBI had closed its last investigation into Andrews' death with a determination that no charges were warranted.

He now says the shooting was an accident, but it's still not clear exactly what happened.