I'm an overthinker and my first guess was that a gun went off in the kid's pocket. My second guess is that he had been saying the right things to the wrong people.
The location where he was shot is screened from the main highway (MD Rt.197) by a lot of trees and screened from the high ground across 197 by the same trees. The intersecting road (Kenhill Drive) is too busy to set up a 200 yard shot and the park to the north of the school has only one way out on to 197 that is always busy.
The local radio stations are constantly covering what Montgomery Co. Schools are and will be doing. The shooting took place in Prince Georges Co. ????
Losts of police and school employee overtime coming up.
The coverage reminds me of the Weather Channel coverage of non-hurricanes.