I agree with Pete Zahut. If all media outlets voluntarily agreed to never mention the name of a gunman it would reduce the frequency of mass shootings.
As for Trump, I think he issues 'dog whistles'. Sooner or later somebody will respond. I don't think for a moment he approves of this incident but his language is careless.
Henry II once said 'will no one rid me of this turbulent priest?'. Four of his knights rode off and murdered the Archbishop of Canterbury, Thomas Becket. Henry was mortified. Words have unintended consequences.