Ilovecheese
I don't see how naming them is going to help Brianna's family.
Nor do I. I'm not sure what I think, really. They don't look like children, but they were 15, which is legally underage, so they shouldn't be treated as adults. Otherwise I have no sympathy with them. The law should be fair to children by recognising that they are less capable of making rational decisions than adults, and this should be applied, but I wouldn't want to see any special leniency in this case.
Whether that means they should be named or not, I don't know. I can't see it making much difference to them either way - they can change their names anyway, and it is likely to be a long time before they will be out in the world. Their families are likely to be suffering horribly (imagine if your child had done something like this), so adding to their misery isn't going to achieve a thing other than some sort of vicarious revenge, which seems to me pointless.
Brianna's family won't gain anything from their being named, unless there is something I am missing, although I do think that they need to be told who murdered their child, to help towards some sort of closure. Their grief must be all-consuming, and I doubt that having the names in the public domain will make a dent in that.
The only real point to naming them that I can think of is if there is anyone else who might be suspected and would be cleared if these people are named. I don't believe that is the case though.