This is a really rough story. Obviously the kid didn't deserve to die for throwing eggs. I wish I could make all parents responsible for their kids actions. Twice in the last five years I have had a back window on my minivan shattered while I was driving. The first time the cops said it was probably a pellet gun and the perps weren't caught. The second time it turned out to be kids throwing rocks at cars. The cops went to the street and got hit by a water balloon as they turned the corner. Kids caught this time and the parents paid for the window.
The catch here? If anyone had been sitting in the seat by the exploding window either time they would have had broken glass embedded in their upper body and face. While cleaning up the glass I got cut more than once. I know the kids in the second incident weren't criminally charged but at least one of the parents called me to apologize and did pay for the damage. They assured me that the kids would be punished at home. I'm so very lucky that my kid wasn't in the back of the car.
The answer? Kids need to know that their actions do have consequences. Again, OBVIOUSLY it shouldn't be death for a prank. Around here kids have to do community service for breaking minor laws. Some kind of punishment needs to be meted out. Something that will impress on the kid that even pranks are irresponsible and punishable.
Unless kids, or other potential criminals, fear the consequences of their actions it does little to change their behavior. Community service IMO is as useless as detention in schools. Bring caning back, at least for older boys, and see the dramatic improvement in behavior.