From what I could remember, "Murder Inc." was a B-17 in the 8AF, possibly in the 100 BG. It was shot down and the Germans played major propaganda because if its name.
I believe "Murder Inc." was the name of an old movie about gangsters (some one correct me if they know more) but where the Nazi propaganda machine really got mileage on this is "Murder Inc." was also the enforcement wing of the mobster Lucky Luciano's Crime family headed by Bugsy Seigle, Albert Anastasia and Louis "Lepke" Buchalter. From what I could remember, the Nazis were trying to portray all Americans as corrupt gangsters.