I used to watch this movie on TV as a kid, and I thought it was great. Now, many years later, I'm not nearly as impressed.
Don't get me wrong: It's still a fairly fun film to watch, but the weaknesses stick out like a sore thumb.
First of all, the acting is almost terrible. It is extremely heavy handed, almost Kabuki in style and manner, and gets to be a true headache after a while. Almost everyone WAY overacts -- and almost all of the gestures are outrageously overplayed. Richard Boone doesn't just put a book down on the table; oh no, he SLAMS the book on the TABLE!! And Jack Webb doesn't just remove a page -- no, he TEARS all the pages out of his NOTEBOOK!! And Ben Alexander RIPS a poster off the WALL!! And other characters STUB out their cigarettes in the ASHTRAY!! And they WHAM the coffee pot down on the COUNTER!! It's almost a parody -- almost like a skit on Saturday Night Live. Needless to say, I found all this hamming it up to be distracting, and occasionally really irritating. In fact, the only person who does NOT shamelessly overact is Ann Robinson as the undercover police officer. She's a real relief for the viewer.
Also, the portrayals are ridiculously, almost absurdly, black and white: The cops are all macho super-dudes, who do all the right things, all the time; and the criminals are all slimy, vicious, scum of the earth, sewer rats -- even the criminal's wives and girlfriends are evil, ball-busting, nasty vipers. It's all just WAY too much. Too over the top. And too one-dimensional and crude.
That being said, some of the camera work is clever, and the editing is quite skillful. Scenes of Los Angeles in the mid-1950s are fun and nostalgic to watch, as well.
And since this is a 1954 production, maybe some of the heavy-handedness, and the almost fascist portrayals of "good" and "evil", are manifestations of that time period. Maybe that was an appropriate style and tone for that particular moment in cinema. But it can get pretty tiresome and excessive to have to sit through, from the vantage point of the 21st century.
And I haven't even addressed the countless protocol violations in the film. Even back in 1954, you couldn't lock suspects up in a motel room for days on end, endlessly interrogating and browbeating them, denying them prescription medication, and forcing them to stub their cigarette ashes out into their own hands (!!!), and all without any legal counsel! Absolutely not. No way.
Anyway, I guess this is an interesting time-capsule of a film -- and it's not boring. But it can be painful to watch.
But if you want to see a film noir with LOTS of subtlety, great acting, brilliant suspense, and a crackerjack plot, try He Walked By Night (1948), with Richard Baseheart, Whit Bissell, Scott Brady, and James Cardwell. Now that's a truly fine film.