What we call the Mafia isn’t what it used to be, either in the States or in Italy. The work of the Italian journalist and novelist Roberto Saviano in recent years has shocked readers with depictions of cities still under the thumb of contemporary crime “families.” These outfits operate without the operatic flourishes associated with such organizations in popular fictions. Saviano’s book “Gomorrah” was made into a bracing episodic film in 2009 by Matteo Garrone.

The less satisfying “Piranhas,” based on a subsequent Saviano book and directed by Claudio Giovannesi, is an “I Was a Teenage Gangster” tale. In its reliance on a conventional narrative through-line, it’s more reminiscent of “The Public Enemy” than “Goodfellas” in spite of its stylings of contemporary cinematic realism.