That seems like a terrible idea and an unrealistic one at that. If someone is calling to report a violent crime in progress, you’re not coming to a theoretical judgement where you have the luxury of collecting facts to make a determination. This is a matter of prudential and practical judgement concerning human lives. It is not a joke. You must respond quickly in case it is true. This is not a horse race. We’re not taking bets on the most likely case. You will lose time if it turns out to be a prank, but the potential risk far outweighs that loss.

This man also didn’t die because he was shot btw. The way you reduce these incidents is through severe punishments for reporting false crimes.