Law & Order: Criminal Intent - Season 5 Episode 10 Dollhouse

After Joseph Sabo is found lying dead in the street, Barek and Logan investigate who was nearby that night that may have had a motive. They are soon led to Danielle Quinn, who had been blackmailing six different men claiming they fathered her child, asking for money. The detectives realise she was the one who killed Sabo, but when none of her victims will testify against her for fear of their wives finding out what they've done, Barek and Logan hit a dead end.