Luigi "Giggino" Nocerino once stalked tourists through the tight alleys of this southern Italian city, snatching bags and valuables to fuel his drug addiction.

Now he looks after his former prey, escorting them through bad neighborhoods and giving tips on how to avoid muggings and where to eat the best pizza.

Nocerino is one of 70 former convicts, including muggers, drug traffickers and con artists, hired by authorities to guide tourists through the art-rich but crime-plagued city and use their inside knowledge of the local underworld to keep visitors safe.

Officials say the six-month experiment that began in May is succeeding in reducing petty crime and preventing the ex-cons from falling back into old habits or joining the ranks of the Camorra, the powerful mob syndicate that runs global drug rings out of Naples.

"I used to hunt for tourists. How things have changed," Nocerino marvels, recalling how he spent more than 10 of his 43 years serving prison terms for drug-related offenses.

Nocerino and his fellow guides roam tourist-filled areas, like the historic center of Naples or its port, wearing bright yellow vests identifying them, in somewhat mangled English, as "Operator for the Urban Tourist Assistance."

Some speak basic English and Spanish but most use Italians' expressive hand gestures to get the message across. They walk around in groups accompanied by a supervisor, usually a private security guard, who knows them and reports on their performance.

Their job can include pointing the way to a monument, helping tourists negotiate a cab fare or walking them to a specific pizzeria or a pastry shop. The service is free and tips are not encouraged.