While the childhood friend from Germany does not think his former schoolmate was capable of planning a premeditated murder, despite his temper, he does remember Gerhartsreiter having an obsession with weaponry.
Gerhartsreiter owned air guns that he would aim and fire at a local church, the former friend said. The pellets would usually just bounce off the windows -- though once, the friend recalls, Gerhartsreiter used a more powerful air gun that actually smashed a window.
He claimed Gerhartsreiter continually bragged about an assortment of handguns and rifles that his father owned. The friend believed Gerhartsreiter was lying, because he was never able to produce any of the guns.
Information from ABC News' Allison Havey and Sarah Amos and The Associated Press was used in this report.