In the second part of a crossover episode featuring the casts of "Law & Order" and "Law & Order: Special Victims Unit," the police probe the gunshot murders of two men but their prime suspect - a serial killer who previously eluded Detective Briscoe (Jerry Orbach) years before - confesses to only one of the slayings. The cops re-focus their investigation of the wayward socialite daughter (guest star Noelle Beck) of a wealthy, politically connected - and threatening - grande dame (Emmy and Tony Award winner Jane Alexander), but the missing link to D.A. McCoy's (Sam Waterston) case may lie in finding a mob hitman (Steve Mones) who appears to be linked to both murders. Jesse L. Martin, S. Epatha Merkerson, Angie Harmon, Steven Hill, Mariska Hargitay, Christopher Meloni, Dann Florek and Richard Belzer also star.