If we were to start withholding names of those who'd committed murder and other seriously violent crimes, it would create a very peculiar environment where speculation would run riot. For example, ordinary people who'd perhaps moved, emigrated, or whatever, might well come under suspicion - simply because they'd 'disappeared'. An environment of continuous speculation... members of the public - who imagine they have some kind of talent as sleuths, would be constantly running to the press with stories and conjecture. We have to know who these people are (in general, not specifically in this particular case), so that the public aren't in a permanent state of playing guessing games.
As for the hounding of the families - especially by the media - that is something that needs to be curtailed. It is not the fault of the justice system that the media, and readers, behave irresponsibly. There should be some limits on what the media is allowed to print - especially if the families are entirely innocent. Perhaps they (media) should not be allowed to name or identify the families involved? I don't know, because obviously those who know the perpetrators will also know who the families are. But conjecture and guesswork by the media is pretty evil. And, if we were never told the names of murderers, I think the hypothesising and theorising would be dreadful.