Theoretically they should already have them. Solingen is a city famous for the production of cutlery, and is where Böker is based among many, many others like Wüsthof, Zwilling, Eickhorn, Wolfertz, etc. It is literally known as the “City of Blades.” The town’s coat of arms has two crossed swords on it.
One wonders if the location of this attack was deliberately chosen for just that reason.
Germany is also well known for having an array of insane knife laws.