hard to believe but not impossible, I killed a large racoon with my benjamin sheridan ( .177 cal, 800 fps at the muzzle ) I put two good shots just behind its shoulder ( crosman wad cutter pellets ) at about 20 yards, that didnt seem to really phase it other then it was bighting itself where the 2 pellets landed the final finishing shot I put a pellet dead center between its eyes at about 10 yards, after flopping around for few seconds it was out for the count. I will give him the benefit of the doubt, but killing animals of the bob cat size with a air rifle is hard to believe but not impossible.

Ive read stories of where 22 cal. air rifles were used by assasins. And have also read about coyotes being taken with 22 cal air rifles and deer being taken with 9mm air rifles, these 9mm air rifles are something else they shoot a 60 grain 9mm pellet at around 1000 fps pretty cool stuff, if memory serves me right I think its RWS that makes that 9mm air rifle.