. >> sarasota county lead homicide prosecutor, karen fraivillig, believed danielle manipulated michaelo kill sam. >> she's a very manipulative person, and she was able to manipulate michael minor, and there's a dead man because of that. >> the question now before the prosecutor, could she prove it in court? >> coming up -- will one lover betray another? >> we were hoping that he would contact us and said, hey, i want to tell you the truth. >> and the lover left behind ponders what might have been. >> was he the one? >> he was the one without a doubt. he still is the one. >> when "dateline" continues. separately. tide pods with upgraded 4-in-1 technology unleash a foolproof clean in one step. aww, you did the laundry! it's got to be tide. ojust one jar of olay retinol24? hydrates better than the $100 retinol cream. for smooth, bright skin or your money back. olay. face anything. and try new retinol24 max. save for being a new customer. save more for adding drivewise. save even more for driving safely. take another look at allstate - and start saving. ♪ >>> of all the homicides karen fra