Remember how "authorities" in Afghanistan made people get on their knees and simply stood behind and put a bullet in their heads... that's what those parents need to have done to them. There is no punishment harsh enough for these kinds of killers and they aren't going to be rehabilitated so just blow them away and don't bother to look back.
A beautiful little girl that someone would have loved to give a home.
I normally don't like capital punishment, but in these instances... you bet, get rid of them!