I've avoided describing this as a terror attack. the paradigm states and state media operate from is terror is an attack on the state. this isn't how it's defined in law but that doesn't matter (see for example the persecution of Luigi Mangione). if political violence is defined as terror you can be sure it's an attack on the state, if not you can be sure it's not an attack on the state.
as such it's more useful describe the magdeburg attack as a spree killing. how do we the public protect ourselves against spree killers in schools, workplaces, places of leisure, etc.