I don't think he'll rat. His wife is too hot for him to rat. Besides, he literally killed this guy in cold blood during the day. He clearly doesn't give a fuck and can live with the fear and respect he has gained now in prison and outside.
Nicodemo didn't kill him.
I think he has 7 charges on him and even though he didnt pull the trigger the jury could get him on the consiparcy charges or should but who knows with a jury? I could see the defense asking the lead detective: "Did my client kill Mr.Pietro?" Detective: "No"...but.... "No further questions."
