You do not fire warning shots. You fire center-of-mass. STK.
I disagree with his prosecution but he was stupid to fire a warning shot. Those almost always get you in trouble.
Do it like that guy in Texas. You’re dead.
Cheaper than a funeral.
There may be some tactical situations where alerting a criminal to the fact that you have a live weapon may be as effective as actually shooting him, while posing less danger to others (e.g. if a direct shot at the criminal would risk hitting innocents, but a safe direction is available for a 'warning shot'). That having been said, firing a solid projectile skyward would seldom be the safest way to fire a warning shot.