Killing cats is never "random killing". It needs to be done everywhere because we now have a 150 MILLION, soon to be 1.5 BILLION within the year, invasive-species feral-cat ecological disaster on our hands all thanks to those who let their cats roam free. ANY cat away from supervised confinement, pet or not, needs to be destroyed ON SIGHT. If you don't destroy the source of all feral-cats too, stray cats, then you'll never be rid of the problem.This youngster should be taught the correct usage of weapons and take hunter safety classes. Then taken out with a certified instructor or hunter to learn to hunt the proper game and not random killing.
Also access to a target range to help redirect that energy and possibly get involved with target competition.
You can thank all those who are irresponsible pet-owners for this.
(That 1.5 billion is actually a convervative estimate, as is the present 150 million. The true numbers of feral-cats spit out by population-growth calculus is closer to 2.4 billion within the coming year.)