It’s quite simple. Many of these people, such as the example child cited in the piece, do their mass shooting for attention. Many serial killers are the same way. In LA (‘Hollywood’), its well understood that the virtually daily high speed police chase is often motivated for the 15 minutes of ‘fame’. Get on TV and a great story on your way to jail and you’ll be the celebrity.
The film Natural Born Killers, as originally written by Quentin Tarantino, was specifically about the effect of media sensationalist reporting in motivating mass murder. While Oliver Stone changed it considerably, enough that Quentin disbanded his name from the film, much of this concept remains in the film.
The expert in the following video even warns “Every time we have intense saturation coverage of a mass murder, we expect to see one or two more within a week.” And as pointed out by the host of the show, more mass shootings is good news for the Media, as their obsession is in reporting more bad news.
(at about 6 minutes)