I hope there will be a translated version of the polise.se post soon.
No, this is not a reference to "gun nuts" - shooting exercises generally are a sport, I know such people, those are not "gun nuts". And the word murder is there to make a point. There is an english saying "to get away with murder" too, so this shouldn't be of any concern.
Wide recognition of the metalab
Is supported by the Pressespiegel.