They did know the risk they were taking, absolutely. So did the AFP who turned them in. These kids were 21- an age when their adult brains and decision making capacities are not yet fully formed.
Would you show such disdain for someone who drives into a tree and dies because they text while driving? They knew the risks and consequences too, right? What about someone who eats their chicken despite it being a little pink because they are so hungry, and dies of food poisoning?
I don't believe anyone ever has the right to say another human deserves to die.
Mercy is about respect for all human life, humility and forgiveness. The OP has clearly stated the purpose of this thread.
(sorry for debating, OP - the post really upset me.)