While you keep following the political lead of your party leaders in engaging a gun control debate the reports you listed show a clear negligence In following procedures.
"In the 77-page report released on Sunday, investigators said school administrators adopted a "regrettable culture of noncompliance" with safety and security measures leading up to the shooting on May 24 at Robb Elementary School which left 19 children and two adults dead. This noncompliance "turned out to be fatal," the report said.
They also "tacitly condoned" unsafe practices by knowingly violating or allowing others
to violate rules that required doors to be closed and locked."