In a comment on down the page, Steve Mertz mentions Gold Medal writer Ovid Demaris. I want to add a little here to my own comment to Steve.
First, for the curious, the title of one of Demaris' Avon books is The Gold-Plated Sewer, and it's a pretty good one. I've never read his Beacon book, Chip's Girls, but it went through a couple of printings, so someone must have liked it. Demaris wrote another for Avon, The Long Night, and I have one Tower book, The Organization Man, and one Signet Book, The Overlord.
Demaris' Gold Medal novels were generally about gangsters, the Mob, the Mafia. A couple of them became movies. Candyleg was filmed as Machine Gun McCain (which might be a better title) with John Cassavetes in 1968. The Hoods Take Over became Gang War in 1958 and starred Charles Bronson. Both are pretty entertaining, at least to me.
Demaris later hit it big with nonfiction books, including The Green Felt Jungle, the story of Las Vegas. I've never read any of the nonfiction, but I certainly recommend the novels, especially the ones from Gold Medal.