I don’t think this perp was smart enough to build a bomb. He might have been smart enough to scribble some of his crap on a coffee can.
He might have attempted to make a bomb in a paranoid shizophrenic hallucination - or whatever it is they have when there is an episode.
With no chance that it would work. It could have just been a bunch of wires hooked up to a clock and he thought it would work.