Mass shooting in the middle school Vladislav Ribnikar in Belgrade

[Jackalope]

Sorry, but we need to work with the data we have. A terrible study is still better than a-priori reasoning, and a-priori reasoning is better than intuition.

Sorry but it's a garbage study written by a hack 

Not to mention that absent some objective criteria "better" is a subjective value judgment.

Also, as someone who works with data every day - garbage data is garbage. It's a bit like a syllogism with garbage premises. Garbage in, garbage out. "BuT iT's ThE bEsT wE HaVE!!!!!1111!!!". It isn't. It's one that produced a result gun nuts like. It's methodology is trash, as a result the data is trash, and it's conclusions are trash.

Kleck's work is oft-refuted garbage and nobody ought spend additional effort to debunk it.