i'm detective barry cherowitz, and with me is ralph welch. >> so, ralph welch tells detective barry cherowitztory how it happened and who all was there. >> so, police get ralph welch talking. and remember, he's a teenager talking to cops. and he spills it all. >> he told you the story about what? about how what happened? >> he told me how they did it. >> how they did what? >> killed gregg smart. >> ralph welch tells police about learning of three teenage boys who went to gregg smart's house that night with the intent to murder him. these are the three boys that welsh names in that interview. billy flynn, pete randall, and vance, aka j.r. lattime. it's startling because they're just high school kids. lattime supposedly waited in the getaway car. >> and so they went there, and they broke in the place. and they set it up to make it look like a burglary. and i guess the guy tried to run or something. they grabbed him, they threw his dog in the cellar. pete said he held the guy's head while bill shot him. >> the juveniles that were involved in the murder, beginning with billy flynn, all of them ha