In part 3 of my three-episode take on Martin Scorcese and Nicholas Pileggi's masterpiece 'Goodfellas', we pick the film up just after the halfway point, which is Tommy's killing of Spider.  Test audiences and studio executives were completely discombobulated by the loss they felt of the breezy, funny, enjoyable glamorization of the gangster life that the first half of the film represents.  And the descent into depraved, violent madness was a truthfulness that not every audience...or cast member... could embrace immediately.

GQ Oral History of Goodfellas.