An old cop trick when they got a hand written note from some whacko was to get that note to the teachers and retired teachers in the area. Often it worked. The teachers were not identified to protect them. Once the bad guys were identified, the rest of the cop work was easy.
This is utter PC Bravo Sierra that nothing has been released. All we really know is that x amount of people have been killed and x wounded.
Interesting point about the teachers. And seems reasonable to hold a small part back for later weedout of false confessors.
Release the handwritings of the letter and tarot cards, release the audio, and post the picture of the suspected French sniper.