[Theohazard]

What I find interesting is that a bullet that goes straight up (or mostly straight up) and falls back to earth is not going fast enough to be deadly under most conditions. At this point the bullet is just falling from the force of gravity alone, and that's not enough to kill except under the most freakish of circumstances.

But when a weapon is fired at an angle, the bullet retains some of its initial velocity and it definitely has enough power to kill when it comes back down.

The problem is that it's difficult to determine what angle is deadly; at what deviation from straight up does the bullet still retain some of its initial velocity? Becuase of this, nobody should EVER fire a weapon in the air, otherwise terrible things happen like in the story the OP linked.