of stoltz then. >> but both sides agree that later on stoltz returned to the scene of the knife withn knife. >> how similar is that knife from the son that killed your son? >> we think it's close from seeing the blade broken off at the trial. >> given the fact stoltz returned to the scene rather than call police, the lusks believe he armed himself not out of fear but revenge. >> i don't think my son did anything wrong that night. i really don't. and i can see when he came back why brian went over here and said, why are you back? i mean, i would have. brian didn't know how to fight against a knife. he was just a kid. and there was no way. and he just slaughtered him. >> i should have called the police. >> why didn't you call the police? >> never crossed my mind. i was so obsessed with getting my things and going. i wanted out of the condominium. i wanted out of that environment. i wanted to go home. i wanted to go back to california where i was comfortable. it was just -- it was like it was just a big mistake to come out to colorado. that's how i felt at the moment. >> along with the