There are 10 "Gangsters Monthly" comics to be collected in Mafia: Definitive Edition. 4 "Gangsters Monthly" comics can only be found during the story missions. The remaining 6 can be found in a "Free Ride" mode.
Achievements / Trophies: Comic Violence (Find a copy of Gangsters Monthly), Picture Book Connoisseur (Find all copies of Gangsters Monthly)
Gangsters Monthly features a series of classic crime capers you may have heard of.
A Trip to the Country (#1) (SM)Related missions: Omerta
You can pick it up during the "Omerta" mission.
All Saint's Day Massacre (#2)
To reach the garden climb over the wall in the parking lot.
An Offer You Can't Refuse (#7)
Beware the Hanoi Hangman (#3)
Jimmy's Vendetta (#4)
Moonlighting (#6) (SM)Related missions: The Death of Art
You can pick it up during the "The Death of Art" mission.
Sarah: Moll on a Mission (#9) (SM)Related missions: The Saint and The Sinner
You can pick it up during the "The Saint and The Sinner" mission. The comic book is located in the bathroom of one of the hotel rooms on the second floor.
Steam Boys (#10) (SM)Related missions: You Lucky Bastard
You can pick it up during the "You Lucky Bastard" mission.
The Mafia Three (#5)The magazine is on the roof of the building.
To get to the roof of this building you have to get in the vehicle and jump off the nearby ramp.
The Racing Racketeer (#8)