[Morrigoon]

Here's another reason... and really, the same reason that names of the dead are not released on tv before the family is notified:
The police generally like to do the notification to immediate family members in case news of the death is so shocking that someone needs to be there to help them deal with it.

So for example, little Grandmere Thibodeaux is walking past a tv in the shelter at the Astrodome, not knowing where her daughter and grandkids are, then happens to glance up at the moment the tv news displays the gruesome image of her daughter's rotting, bloated corpse. Little Grandmere Thibodeaux is so shocked, she collapses, bonking her head on the cold cement floor. Now two people are dead.

On the other hand, it could be some months before someone processes the dead properly (by which time little GT will probably suspect something, but not be smacked upside the head with it), and a police office comes to little GT, asks her to sit down, then delivers the news. Much better, no?