she assassinated bruce dodson. he didn't even have a chance. i wouldn't call her a black widow. i would call her a greedy assassin. >>> a murder victim's son was the first to suspect that his mother's death was the work of a serial killer. investigators hoped that cells found on a styrofoam cup, marks on a water faucet, and the clues left on a secret video tape would reveal the true identity of a man who had eluded police for over a decade. >>> by 1991, 42-year-old nancy ludwig found what she was looking for in life, a husband who adored her and a career in the airline business. >> she had always wanted to be a flight attendant, from when she was a young girl. very outgoing, spontaneous, adventuresome. that's why she made such a good flight attendant. >> during one of her out-of-town trips, an airline employee called art ludwig with some bad news. >> it was some woman explained to me that there had been a problem in detroit and i should get myself ready and get out to the airport and they would meet me there and we would fly to detroit. >> nancy ludwig was found dead in her hote