A primacord necklace would be fast and painfree!. I’ve heard that when one of the vest bombers goes off they often find the head in pretty good shape, just well separated from the pelvic area!
OK - This is the last time I’m gonna warn you. NEVER light a short fuse off your cigarette !
The school is a few blocks down the street from my house, I had to detour around the condoned off area to pick up my wife at the Main Street Metra stop.
The park and public tennis courts adjacent to the school grounds are a block from commercial area of older stores and shops, in a mostly residential areas of older homes. It’s considered a good neighborhood, where for example many homes which were extensively upgraded during the early part of the decade. It’s the sort of neighborhood where when I walk my wife to the station in the morning there are a lot of dog walkers, and runners and other commuters walking to the Metra and “L” stations out and about.
Anything is possible of course, but to the extent the neighborhood suggests the type of person involved, my money is on a mentally disturbed loner rather than a criminal or terrorist conspiracy.