>> she had broken her heel and she says somebody was stalking her. it's fine. it's okay with me but we had people threatening us in the past, okay? i don't know what's going on. i believe that's what caused the fire. i believe somebody was threatening us. >> so was paul zumot on to something? detectives went to talk to the brothers and, of course, checked to see where both men were the day of the fire. and there was no doubt they were nowhere near the fire. they had alibis. >> at the time of the fire, we know exactly where both of them were. one of the ghanma was in their cafe, and he's on videotape and the other was at fry's electronics and home depot 20 minutes away. we have videotape and receipts from both of those locations. >> so once the ghanma brothers were in the clear, cops do what they always do in cases like this. it's practically police work 101.