Murder via a 'school shooting' or any other Murder is a State crime, violates State laws. Firearms, purchase, possession, use, misuse, and use in a crime is a State issue, involves State laws, State prosecution.
School is a State responsibility, including security of students in a school. Gun free zones is a State declaration, and maybe local government as well, and not a Federal responsibility.
Gun laws is an area of State and Local law, and is written by State legislators.
Congress is a Federal body, not a State body, responsible to address Federal law, and Federal issues, not State law, and State prosecution and State issues.
Duh. What some Congress, or Senate elected official thinks or says is not relevant when it regards things over which they have no authority or control.
Want a change in gun laws in your State? Contact your State legislators. FL Governor Scott is involved and active, regarding the FL school shooting, and welcomes your messages. His office and the FL legislature may act, can act if any new legislation or procedures are needed.