MOLOCH:
Edgar Jacobi, the man known as Moloch, was a famous magician and apparently ran underground vice dens. He was a major target for the heroes and ended up spending a decade in prison. After getting out of prison, Molich went legit and became a businessman. He contracted cancer from his time at Dimensional Developments and eventually was murdered by Adrian Veidt to set up Rorschach.
BIG FIGURE:
Big Figure was a midget crime boss, and one of Rorschach's arch-enemies. He attempted to take revenge on Rorschach when he encountered the vigilante in prison, but the tables were turned and Rorschach drowned him in a men's room toilet.
THE TWILIGHT WOMAN:
The Twilight Woman apparently had some sort of sexual obsession with Nite Owl, who sent the vice queen to prison in 1968. He had an autographed photo of her in a black leather jumpsuit posing in his trophy area.
UNDERBOSS:
Underboss was a crime kingpin that Nite Owl and Rorschach took down. There was a real man nicknamed Underboss in the 1980's, a mafia kingpin.
JIMMY THE GIMMICK:
Probably a criminal that used gimmicks.
THE KING OF SKIN:
The King of Skin was most likely a vice king.