Doesn’t matter WHY he was running away; he WAS running away, therefore there was no immediate threat to the officer or any body else. I have yet to here about the criminal who can outrun a police radio. Unless he was armed and a wanted dangerous felon, there was no good reason to shoot him.
A police officer is only supposed to shoot to eliminate a threat, where was the threat?
In my opinion the cop lost his self control, panicked and committed a murder.