More at NoirOfTheWeek:
The source material for Crossfire was a novel, The Brick Foxhole, by Richard Brooks, in which the murder victim is not Jewish, but is instead a homosexual. In the novel, there is more emphasis on the primal struggle between Keeley and Montgomery (whose name in the novel is Monty Crawford). John Paxton’s adaptation eliminates this confrontation, and substitutes the low-key tenacity of philosophical cop Finlay. The resulting cat-and-mouse game between Finlay (extremely well-played by Robert Young) and Montgomery becomes the film’s essential fulcrum.
As noted by Naremore and others, the scene where murder suspect Mitchell first encounters murder victim Samuels (another fine performance from noir veteran Sam Levene) has a certain sexual ambiguity to it. The camaraderie among men that is displayed throughout Crossfire has a consistently pointed tone, and it is never portrayed as exactly “normal.” Having won a war against dark forces, the men returning to their homeland encountered a changed landscape: Crossfire depicts the deep-seated nature of that disorientation and its potential for damage (Mitchell’s emotional distress) and violence (Montgomery’s unprovoked attacks).
Crossfire’s backstory is so rife with ‘ironies’ that it’s revealing of the dangerous currents in which the project moved. (…)
Today Crossfire remains interesting not for tackling anti-Semitism (Robert Young’s stultifying lecturing in the film sees to that) but as one of the films in which Hollywood provided a window into the ‘postwar malaise’ syndrome. Counter to the expected elation following global victory, a surprising flatness and quasi-depression was evidently widespread in America after the war. Of course back then there was no counselling for re-entry and readjustment to civilian life. A handshake and a bus ticket – if you were lucky – was it.