terry? >> reporter: a lot of people have been following the disappearance of kevin collins for many years. tonight i spoke with steven collins, kevin's brother. he said he has seen many breakthroughs over the years, but this one looks like the real thing. this is the person of interest in the disappearance of kevin collins. this is man san francisco police knew mostly as wayne jackson. he had at least four aliases, and that's what threw police off his trail. >> based on jackson's description, his residence on masonic avenue, his ownership of a large black dog, and his criminal history, we are investigating jackson as a person of interest in this case. >> reporter: jackson was 6 feet tall, blond, and had a black dog, just like the person last seen talking to collins in february of 1984 at masonic and oak streets in san francisco. jackson lived on masonic. >> it's hard to look at it and not think, you know, that this is it, or this was very, very likely that this is what happened. >> reporter: kevin's brother steven found out last night from police that when kevin vanished, officers knew of