referred to him as a monster. here they were this morning on "good morning, america." >> everything everybody seems to know, we didn't know. we had rules. he followed every rule to the t. >> before he moved into your home how well did you know him? >> i met him a couple times before. he was polite. he seemed normal. >> when did you realize what he had done? >> after the s.w.a.t. team called me and asked if i knew where my son nicholas was. i said he's not my son but i don't know where he's at. i got in touch with my son who was fleeing the scene at that point. a description came out. we put two and two together, me and my son. we figured out what was happening. >> you were aware he had weapons when he moved into your home? >> absolutely. >> where were they kept? >> before he moved in one of the stipulations is he needed a gun safe. we got a gun safe on the way