never had him coming outside of the house or we never had him going inside the house. reporter: according to rob s friends, someone had been stalking him. about a year earlier, they said rob told them he d gotten some creepy emails, which suggested that he was being watched. this is one of them rob, saw you this morning with this woman on upper west side. how are things with her? very, very strange email addresses, strange names. one was e-o-r-a-l-l-d. another one was e-o-r-2-4-7. reporter: assistant prosecutor brian sinclair who heads the county s computer crimes unit, says the emails seemed intended to intimidate. imagine that rob was getting these emails, being quite troubled that somebody knew where he was at a particular time, you know, who he was with. reporter: with that in mind, the prosecutor and his top detectives decided to take a hard look at rob s personal relationships, starting with his wife of 27 years, susan
stranger near the cantor home shortly before the fire. did you hear about the stranger that was in the area? yes. can you tell us about that? yeah. we weren t able to track who the person was and we tried through canvassing to trace, but we never had him coming outside of the house or we never had him going inside the house. reporter: according to rob s friends, someone had been stalking him. about a year earlier, they said rob told them he d gotten some creepy emails, which suggested that he was being watched. this is one of them rob, saw you this morning with this woman on upper west side. how are things with her? very, very strange email addresses, strange names. one was e-o-r-a-l-l-d. another one was e-o-r-2-4-7. reporter: assistant prosecutor brian sinclair who heads the county s computer crimes unit, says the emails seemed intended to intimidate. imagine that rob was getting these emails, being quite troubled that somebody knew where he was at a particular tim