Putting together the puzzle: School teams assess threats

In this Sept. 6, 2016, photo, students at William Hackett Middle School pass through metal detectors on the first day of school in Albany, N.Y. Schools around the country have been setting up teams to assess threats posed by students who display signs of violence like the former student who compiled a “hit list” years ago in high school and went on to kill nine people in a weekend shooting in Dayton, Ohio. (AP Photo/Mike Groll)

There were so many questions after 17-year-old Ely Serna brought a shotgun to his Ohio school and opened fire in 2017, wounding two.