The names behind Thursday's horror in Bend, Oregon are now public. Police have identified the gunman as Griffin J. John II, 16, of Bend — a former student at Silver Rail Elementary School who had attended its special-needs program — ABC News and NPR reported on Saturday.

John forced entry by firing through locked doors around 1 p.m. Thursday. Three children and one teacher were killed, all inside a special-needs classroom: teacher Megan Lambert, 25, and 5-year-old Rhoam Summer were named; the two other boys, ages 8 and 11, are being withheld at their families' request.

A 7-year-old girl was serious but stable by Friday, and 54-year-old education assistant Rebecca 'Becky' Drury was seriously injured but not in life-threatening condition.

The gunman was shot and killed by Kaylub Giamanco, a 36-year-old father of two students who legally carried a gun in his car; Bend Police Chief Mike Krantz also credited a teacher who tackled the attacker. President Trump praised Giamanco on Friday. The motive remains unknown, with the ATF and FBI assisting the investigation.

The identifications move the story from shock to accountability: investigators must now reconstruct how a 16-year-old former student obtained a weapon and breached a locked school, and what, if anything, was known about him beforehand.