So he removed his fingerprints and had no ID on him. I guess he had a plan of some sort.
Yeah that doesn't sound spur of the moment to me. All threats have to be taken seriously.
I'll throw this out for discussion: was there a snowball's chance in hell of there being ANYONE armed in that building? Maybe not a GFZ (haven't done the research yet) but Maryland is pretty close to an "only criminals are armed" state. Psycho no fingerprints guy didn't engage the LEOs, he wasn't looking for an armed defense.