I first saw this in the mid '80s and thought: 'what a stylish thriller!' It seems to have been filmed in a low-grade film stock, which has given it a grainy/soft-focus look which also adds to it's realism. Elliot Gould, who stars as one of the hard-bitten cops also appears in another Peter Hyams opus, Capricorn One. Robert Blake who plays Gould's partner, later featured in his own TV detective series called Baretta.
There are some wonderful set-pieces in the movie, the best in my opinion involving our heroes chasing some bad dudes from a seedy hotel, and through a supermarket on the streets. It's classic Cat-and-Mouse fare, as the villains take a hostage while Gould 'n' Blake have them firmly in their gunsights. This moment is ingeniously realised by Hyams' use of a wide-angled lens. There are also brilliant car chases galore to marvel at.
Anyone who is a fan of this type of gritty cop thriller with a downbeat ending, would enjoy another good example: William Friedkin's 'To Live and Die in LA' (1985) which stars C.S.I.'s William Peterson.