Welcome. That was the first story about it I read today, and I thought others might want further info as well.
Instances like this are where I have to think the eye for an eye idea proposed in the Bible is really appropriate...these people should get the death penalty, and it should be administered by torturing them the same way they tortured this little girl, possibly the younger two as well. A bullet would be too fast and painless...
I think staked out 10 feet from an ant bed with about a tablespoon of honey between the legs might work...