A masterpiece of sexual creepiness, institutional corruption and suffocating, ugly passion. -James Ellroy, novelist (L.A. Confidential; The Black Dahlia) commenting on this film noir (his favorite movie)
I learned re: The Prowler while listening to The Big Picture podcast ep w/ guest Patton Oswalt; he’s also a big fan of the noir genre. John Huston (uncredited producer) conceived this project as a star vehicle for former wife, Evelyn Keyes, as a parting gift. She’d complained about her lack of challenging roles while under contract at Columbia Pictures. Keyes is best known as Sue Ellen, Scarlett O’Hara’s lil sis on Gone With the Wind (1939), though she appeared in many other films. I saw her in The Killer Who Stalked New York (1950); this is relatable in today’s pandemic life.
In an affluent suburb in SoCal, blonde/glam housewife, Susan Gilvray (Keyes), sees a prowler outside her house late at night and calls the police. Officer Webb Garwood (Van Heflin) and his partner, Officer Bud Crocker (John Maxwell), answer the call, but don’t find anyone. Later that night, Webb returns to Susan’s house with the pretext of checking if everything is OK. Susan (a former actress) invites him in to have coffee; it turns out they’re from the same small town in Indiana. Susan is married to the broadcaster of a late-night radio show; they don’t have any kids. Webb comes by another night and kisses Susan; she tries to put him off, but they soon become involved romantically.
Webb: [picking the lock of her husband’s storage box to get some cigarettes] Does he keep everything locked up?
Webb: You, too?
Susan: That’s a leading question.
Webb: Ha, probably does. A mean, jealous guy like that wants his wife all to himself. I can’t say I blame him, though. I’d do the same myself…
Webb: [opening the storage box] There. See how silly it is to keep things locked up?
Susan: Maybe. But it did delay you for a little while.
Webb: Is that all he wants, just to delay things?
Susan: Sometimes a little delay does the trick.
This film was considered shocking in its day; after all, it focuses on a cop that’s a bad guy. Heflin shifts about, scratches himself, and moves like a panther. Webb is an expert in gaslighting; he uses psychological manipulation to put self-doubt and confusion in Susan’s mind. Eddie Muller (host of TCM’s Noir Alley) became good friends w/ Keyes later in her life; this was her fave role. Muller noted that this film can be looked at through the lens of a woman desperate to have a baby. To bring attention to this issue, the song “Baby” is repeated a few times throughout the film.
 Very much a two character piece, The Prowler flips the favoured femme fatale formula around to great effect. Here it’s the male protagonist that is the seducer, a cop no less, the abuse of power hanging heavy over proceedings like, yes, some “prowler” lurking in your back garden. It’s made clear to us very early on that Garwood is troubled, he’s up to no good, with a snarl here and a shifty smirk there, we just know that poor Susan is under threat from a man meant to protect her. […]
A criminally undervalued actor in his generation, Heflin serves notice here that he could play a bad guy convincingly, almost terrifyingly so too. His shift from meek, almost puppy dog love yearner, to conniving bastard is handled adroitly and gives film noir one of its best homme fatales.
 This is the kind of film noir that has its foot rooted in the ‘B’ tradition. What I mean is Losey and his writers (including blacklisted Dalton Trumbo) are keeping their aims low, and scoring high within their limitations.
 It is very beautifully and atmospherically shot and tightly edited, although the sets are on the sparse side. While it is not exactly lavish or expensive-looking, ‘The Prowler’ also doesn’t look cheap. The music looms ominously without being intrusive. Joseph Losey… directs with a sure and stylish hand, that indicates somebody who knew what he was doing. The script on the most part is taut and intelligent, and it was amazing too at how daring and subversive it was for back then.
-Excerpts from IMDb reviews