Gavin de Becker wrote about this in The Gift of Fear. The media reward the mental nut-job murderers with the celebrity & attention they crave, thereby alerting the other nut-job would-be psy ho’s (typo and it stays!) that they can bank on getting the same kind of media attention & instant celebrity by acting on their own sick fantasies. Which in turn gives the media more It Bleeds, It Leads stories, which encourages more psycho’s to act out... lather, rinse, repeat.
Yes, that is the dynamic. The media profit from the carnage and use it to push their agenda.