Personal note: At the time, I was a teacher at the Cambridge School of Weston. School shootings were in the news a lot, and this was the worst of them all. I remember a lot of discussion among the faculty about how to deal with the issues brought up by the shooting, and we ended up having a community meeting where students could discuss the issues that concerned them. I can only hope that it was helpful for them.
These past few days of April haven't been good ones in recent history. So let me also add that on this day in 1841, Edgar Allen Poe's story "The Murders in the Rue Morgue" first appeared in Graham's Lady's and Gentleman's Magazine. The tale is generally considered to be the first detective story. The story describes the extraordinary "analytical power" used by Monsieur C. Auguste Dupin to solve a series of murders in Paris. Like the later Sherlock Holmes stories, the tale is narrated by the detective's roommate.