On September 15, 1973, a shooting at a Springfield, Missouri residence left 32-year-old Coffier Eugene Day dead. Knighton produced a pistol and fired; Claude Day was shot in the neck and survived, while Coffier Day was struck multiple times and died of his wounds.

After the shooting Knighton fled on foot, then forced the Jarrett family and their young daughter at gunpoint to drive him away, taking them hostage. Law enforcement intercepted and arrested Knighton without physical harm to the hostages. Knighton was initially charged with first-degree murder but later pleaded guilty to a reduced manslaughter charge and was sentenced to ten years for that conviction, to run consecutively with additional sentences for kidnapping and robbery imposed for the other crimes.

If anyone knew Coffier Day or has information about the events of September 15, 1973, please share what you know.