speculation about that woman in the firm who d been killed. whether melissa knew about the ponzi scheme is one of those great mysteries. reporter: scott had started his ponzi scheme three years before melissa was murdered. is it time to take a fresh look at the whole melissa lewis murder? is there something more sinister? reporter: detective brian kendall now had a whole new problem with his fairly straightforward case against tony, the jealous train engineer. is this woman, melissa, killed because she knew too much? after we think we had this solid, buttoned-up case, we do have the whole scott rothstein ponzi scheme comes into play? reporter: the fbi combed through the detectives files looking into a melissa-rothstein-ponzi link. they spent a week going through every inch of that case to find out if there was a connection to scott rothstein. reporter: with all these messy complications, tony s
2010, he was sentenced to 50 years in prison. but one big question emerged, speculation about that woman in the firm who d been killed. whether melissa knew about the ponzi scheme is one of those great mysteries. reporter: scott had started his ponzi scheme three years before melissa was murdered. is it time to take a fresh look at the whole melissa lewis murder? is there something more sinister? reporter: detective brian kendall now had a whole new problem with his fairly straightforward case against tony, the jealous train engineer. is this woman, melissa, killed because she knew too much? after we think we had this solid, buttoned-up case, we do have the whole scott rothstein ponzi scheme comes into play? reporter: the fbi combed through the detectives files looking into a melissa-rothstein-ponzi link. they spent a week going through every inch of that case to find out if there was a connection to scott rothstein. reporter: with all these messy complications, tony
ponzi scheme comes into play? reporter: the f.b.i. combed through the detectives files looking into a melissa-rothstein-ponzi link. they spent a week going through every inch of that case to find out if there was a connection to scott rothstein. reporter: with all these messy complications, tony s defense attorney, bruce fleisher, thought about two words, reasonable doubt. a lot of people thought that because of the rothstein ponzi scheme, that he had something to do with the murder of melissa lewis. reporter: and debra villegas was back in the hot seat herself, being grilled by homicide detectives who bluntly asked her about scott, the ponzi scheme and melissa s murder. she had her lawyer with her this time. was melissa aware of anything that scott was involved with? and i m i m gonna use a term the ponzi scheme. no. reporter: and then the questioning got more direct. any discussion between you and scott about having melissa killed? absolutely not. are you awa