I think if someone tried real hard, they could make a federal case. And local jurisdictions can request FBI assistance.
Unless they would try to shoehorn into a civil rights issue, there is very little federal justification.... and you can’t chase every tip into a federal matter.
Also, FBI wants to keep best relations with local LEOs, especially elected ones like Sheriffs, so the locals will call them when they have info involving wide areas matters outside the local jurisdiction.
The SA should have called the Parkland cops or Broward SO immediately, however in this case.