This guy is not—IMO—a schizophrenic (I am a physician, but not a psychiatrist). Schizophrenics cannot plan like this guy did, nor could someone in the throes of this most serious mental illness do what he did in booby-trapping his apartment. Ted Kaczynski was not schizophrenic, nor was the Norwegian shooter Breivik. Perhaps borderline personality disorder or other diagnosis fits best. I would bet on drugs (legal and/or illegal) as being the main culprits with this dude’s descent into mental hell.
“Why am I here?” = I am the victim.