Sonny learned earlier this week that Dominic was an undercover cop after telling him last week he'd like to turn the "business" over to him some day. He called him to his office and confronted him. Dominic pulled out his badge and stated that Sonny was under arrest. Sonny pulled a gun and said his body would never be found. Dominic explained why he hated Sonny (he'd had a police officer in their neighborhood in Brooklyn, who helped Dominic out when he was growing, killed), and then Sonny shot him in the chest. Olivia (Dominic's mom) burst in, screamed as she dropped to her son's body, and turned to Sonny saying "You shot your son". All of which was happening during Jocelyn's christening, where Jason and LuLu were serving as her godparents.
(The audience knew Dominic was Sonny's son, but neither Dominic or Sonny knew.)
So, what will Sonny's reaction be and is Dominic going to live?!
(For anyone who watched BSG, Dominic is portrayed by the same actor who played Jammer. I have a bit of a crush on him.)