User blog comment:Gaarmyvet/Other Grimms/@comment-5116706-20121024004628/@comment-1114229-20121024011740

They have a database of "available Wesen" by type? They tell their tame Grimm to dispatch the Wesen and have the Wesen report directly to the Royal. Wesen that don't perform are hunted down and killed. All supposition, of course, and presumes more Grimms than we can imagine.