brian kato kaelin: i invited myself. he didn't ask me, and i thought, oh, i was starving. josh mankiewicz: kaelin told detectives they got back around 9:40 pm. he returned to his bungalow and didn't see simpson again for approximately an hour and a half. then, around 10:45 pm, kaelin says he heard three strange sounds. brian kato kaelin: it was a loud-- it was a banging noise as if someone bumped into a wall. josh mankiewicz: kaelin came outside to check on the noise and saw limo driver allan park at the gate, waiting to take simpson to the airport. a few minutes later, simpson came out of the house. his luggage was loaded and the limo sped off. kaelin's story seemed to add up. so now it was simpson the cops really wanted to talk to. he was in his hotel in chicago when detectives told him what had happened in la. there were no details given except that nicole was dead. he said, i'll be on the next plane back there. josh mankiewicz: now, came another phone call. the one tom lange dreaded, notifying nicole's family. you hear that phone ring and i hear a scream from my mom's r

whose side was kato kaelin on? oh, that's a great question. he certainly wasn't on ours. he was on kato's side. that would be my opinion. from the very start, he was very clearly withholding information. and you didn't think he had anything to do with it? no. what he was doing was sticking his finger in the air, seeing which way the wind was blowing and saying, you know what? simpson's not going to get convicted, and i'm going to be the one who is standing by his side, and he'll take care of me. josh mankiewicz (voiceover): kaelin told us he cooperated fully, and answered everything clark asked. and at trial, he did detail a critical sequence of events before and after the murders. from the trip he and simpson took to mcdonald's, to those three strange sounds he heard at 10:45 pm. sounds investigators believed simpson made when returning home after killing ron and nicole. marcia clark: can you demonstrate for us how loud it was? somewhat yes. marcia clark: go ahead. yeah, go ahead. and where did that noise seem to be coming from? from the back of the wall. josh mankiewicz