Question: can a bullet fired into the air kill

Answer: Yes, Bullets fired into the air usually fall back with terminal velocities much lower than their muzzle velocity when they leave the barrel of a firearm. Nevertheless, people can be injured, sometimes fatally, when bullets discharged into the air fall back down to the ground. Bullets fired at angles less than vertical are more dangerous as the bullet maintains its angular ballistic trajectory and is far less likely to engage in tumbling motion; it therefore travels at speeds much higher than a bullet in free fall.