They're under 18, which if American law is like ours they're basically going to get away with murder. They'll spend a few years in jail and get out in their early 20s or so, perhaps the 17 year old will be tried as an adult. It's disgusting.
I'm sure the death penalty will be waiting for them the next time it happens, it's not like we've got any reason to believe they won't do it again.