This and DEEP COVER
This film and DEEP COVER, while tonally quite different, both portray undercover work as little more than a political check of limited effectiveness against the underworld economy -- Its agents to be sold out at a moment's notice when their investigations, however shaky, threaten the business interests of protected higher-ups. In this case, Will Gaines.
Gaines knows Raynor is a cop from the opening shot when he glowers at him before hopping in his Benz. Without ever having a character make any exposition-dump speech, the film subtly implies Gaines has juice with authority figures higher than the very department desperately trying to build a case against him. This is how he knows to pull his head in and conduct business through a bevy of intermediaries. This is how he knows where Raynor and Kris are hiding out.
It's disturbing AND disturbingly accurate.
In DEEP COVER, Goldblum says of that film's kingpin: "Hector Guzman goes fishing with George F|_|CKING Bush!"