:::I came in on this through seeing it listed as a content dispute at WP:3O a few weeks ago, and the discussion above gave me the sense that this article may have a more-than-usual amount of WP:COI going on with it.  Which had flared up into edit-warring, too, so there also seems to be conflicting conflict-of-interest going on.  So, for my part, I am taking a conservative stance with regard to the text as it is now.  Though I have made several changes to it myself after first discussing those changes here, on this page above – including the wording in the lead you are questioning. 
 :::I'll consider further the points you are making about that and respond below. 
 :::Interesting that the article existed pre-shooting, I hadn't known that.  But, it wasn't until after the shooting that the article even had a reliable source, and that was about the shooting.  Before that, the article clearly met the criteria for deletion (unsourced and non-notable) and could have been at any time up to that point if anyone had wanted to bother.  I'm sure you'll agree that the shooting and what came out about Ganas' history and "controversial" practices in eg. the New York Times as a result of the shooting are going to continue to feature prominently in our article.   ☯