Gangsters

Members of a thieves guild don't usually fit the picture of gangsters, but are essentially the same.

Generally speaking, gangsters are commonly involved in more elaborate illegal schemes, such as protection money scams (protection from themselves, and possibly other gangs), money laundering, black market, lending (in fiction often with intent on abusing the debt), and so forth.

As a bit of trivia, government security agents are often depicted in a gangster like way, drawing some parallels.

Related:
* Organized crime