Absolutely. Police depts have a large and detailed ops handbook. An active shooter definitely supersedes a barricade situation. Barricade situations require that you wait for SWAT, which I assume is why they waited for border patrol. A lot of small depts don't have a swat team.
So 2 questions:
1. Why the ***** did they treat this as a barricade situation when it was obviously an active shooter in a school with small children? This seems like common sense, but with someone in a high pressure, life or death situation they often make stupid mistakes.
2. Why can't they have a SWAT team with a apparentky a budget of $4 million?
These are just questions popping into my head, but I know there are still more details to come out.