Mulholland Falls

This film is about the adventures of a 1940's special anti-gangster police squad in Los Angeles, the infamous 'Hat Squad.' The four members of this squad are big, tough, no-nonsense cops who don't hesitate to break the law, if it suits their purposes. When a local woman is murdered, their investigation turns up the fact that she had been romantically linked to several prominent men and had secret films taken of her liaisons. Since one of those men is the powerful U.S. Army General at the head of the then-new Atomic Energy Commission and another is the (married) leader of the Hat Squad, complications ensue. The FBI even gets involved in an attempted cover-up.

Billy's only in the movie about the first 15 min or so.
(uncredited) .... Jack, Mafia Mobster

Tagline: This isn't America, this is Los Angeles

Cast overview, first billed only:
Nick Nolte .... Max Hoover
Melanie Griffith .... Katherine Hoover
Chazz Palminteri .... Elleroy Coolidge
Michael Madsen .... Eddie Hall
Chris Penn .... Arthur Relyea
Treat Williams .... Colonel Nathan Fitzgerald
Jennifer Connelly .... Allison Pond
Daniel Baldwin .... McCafferty
Andrew McCarthy .... Jimmy Fields
John Malkovich .... General Thomas Timms
Kyle Chandler .... Captain
Ed Lauter .... Earl
Larry Garrison .... Perino's Maitre d'
Chelsea Harrington .... Lolita
Johnna Johnson .... Bar Woman