"3 Dog Night" is the name of an American rock band originally formed in 1967.
Interim District Attorney Nora Lewin suggests that Assistant District Attorney Ron Carver--a character Courtney B. Vance was playing in the spin-off series Law & Order: Criminal Intent (2001) --should sit second-chair on this case. The idea of having a black A.D.A. at the prosecution table is likely a reference to the Los Angeles County District Attorney's Office having Christopher Darden, a black A.D.A., as part of the prosecution's team in the O.J. Simpson murder trial case. (Courtney B. Vance had guest-starred twice previously in the original Law & Order series.)
This episode appears to be based on the shooting at Club New York involving music artist Sean 'Diddy' Combs (a.k.a. "Puff Daddy)".
Sharrieff Pugh (Marcus) previously played the role of Fontaine in Episode 2.19, The Fertile Fields (1992).