"The police are often very good at using their interpersonal skills to persuade idiots like this to do the right thing without resorting to demands or force."
I've never met a Police Officer with interpersonal skills. However I agree with what Cakeinatin did and it should be part of the Police's remit to stop such an act.
People should be told when they are behaving in a moral reprehensible manner. It depends on how it is handled and what the photo was going to be used for. I think that pictures of Joe Bloggs should be as protected as pictures if Lady Diana, for example.
Is consent ever obtained for the images of dead children sent to the UK, by UK citizens, though?
It's a grey area what makes something "In the interests of the public", a family member of mine was wrongly accused of murder (of a child) and their picture was put on the front page of a Newspaper, which ended with them having to leave the UK, no compensation was ever given.
There are aspects of the Hillsborough disaster and press involvement that is certainly morally reprehensible, so I can understand the points that unless an individual is doing something illegal, the Police shouldn't use their powers, they certainly wouldn't if it was anyone in a position of power that was doing so.
Who would want to open FB and see a picture of their dead friend or relative, unless they were caught up in a disaster and you were looking for them?
But then what family wants a suspects face in the press for them to also suffer a backlash (as happened in my family).
In the OP's situation, if it was just the emergency personal in the picture and it was put on with a warning, then I think that, that is acceptable.