poured over bus schedules, taxi and limo records and in the end they came up empty. >> you had no bridge video, you had no taxi receipts, you had no witnesses. you had nothing physically placing tony there. >> you're right. we didn't have him at the george washington bridge. we didn't. >> still the investigators kept digging. remember the anonymous e-mails sent to rob suggesting that he was being watched, turns out they all traced back to tony. >> he created all of these on the same day which was the same day that he learned about the affair. he used these e-mail addresses to start contacting mr. cantor. at some level trying to shame him into stop having an affair with his wife. >> that wasn't all. a close look atony's computer indicated a massive amount of data was destroyed on the night that rob cantor died.