This all presumes that the media DOESN’T want more mass murders they can use to sell soap, along with their anti-gun leftist agenda.
Honestly, I believe that a federal prohibition on revealing such information would NOT violate the first amendment (for public safety reasons.) I may be wrong, but some enterprising Congressman seeking to get some national attention could introduce such a bill, and start the dialogue (”voluntary” media standards might result.)
Without pictures how is the media expected to get gun control to beccome a primary MUST DO issue?
If the prohibition was on publishing, they it would violate the first amendment. But in spite of what the press might say, there is no right to "know" such information, so if the police and others don't reveal it, it will be less likely to be blared out of every media orifice. The same is true of the tapes of the scum "in action", audio tapes of the event and so forth. Probably it will still get out, eventually. But by that time it won't be worth the wall to wall coverage that these things tend to get now.