They Call Me Mister Montalban
Rare enough, in 1950, to have an antihero who was also a cop. Vaguely acceptable provided Good Triumphed in the End, but rare. I mean, Good had to Triumph in the End no matter what, of course, but there was a much larger requirement that Our Protagonist be redeemed by the end of the picture if he were an authority figure. (No, really. It's in the Code. No mocking authority figures.) However, it was known to happen. It was also rare to have an Ethnic hero. Sometimes, you got guys playing Ethnic People who were actually born in New Jersey or whatever--Marlon Brando was actually, honest-to-Gods born in Omaha. A guy born in Mexico City? Don't be ridiculous! And so I must bring you to the most interesting thing about this movie. Our Protagonist is an antihero played by Ricardo Montalban. Really.
However, we start with Vivian Heldon (Jan Sterling). She works in a seedy dive called the Grass Skirt. One night, she hooks up with Henry Shanway (Marshall Thompson). He walks her out of the bar and past A Tattooist (Ralph Dumke, and yes, that's the character name), and she is never seen again. Well, until An Ornithologist (Walter Burke) finds her skeleton instead of the, you know, shore birds he's actually there to find. Peter Moralas, who formerly worked in the Portuguese community, is now brought on to solve the case of "skeleton girl," as the paper calls her. Of course, your first step there is proving that the skeleton was female; that's easy. I can do that. Dr. McAdoo (Bruce Bennett), however, is actually able to find out a whole lot more, and Montalban starts his pursuit of the killer, whom he assumes to be Shanway.
There's some serious Code-dodging going on around here. Vivian had lived in a boardinghouse run by Mrs. Smerrling (Elsa Lanchester), a grasping, petty woman. Who admits to Montalban (who cares what his character name was?) that she was never in so many words married. It's also possible that Vivian was a prostitute, given that Montalban has an address book of hers with the names of eighty-odd men in it. When Shanway is in the Grass Skirt at the beginning of the film, he has left his wife's side; Grace (Sally Forrest) has just lost their baby. Shanway is drunk and in despair, and it's pretty clear that adultery is a distinct possibility. The Tattooist pretty much assumes that's why they're going home together. Grace seems as worried about his possible adultery as that he might have killed a woman.
There's also some pretty interesting forensics work involved. Dr. McAdoo is a major character, his work in many ways as valuable as Montalban's in identifying Vivian and learning what they can about her. I'm pretty sure their technique of superimposing slides of missing women of about the right age onto a picture of her skull is . . . not the most useful method of identification, but it's not hugely removed from the techniques used to identify skeletal remains today. It's also true that the information given about how bones grow and stop growing, the information which helps determine Vivian's age, is actually medically valid. There are several details in the movie which aren't as ridiculously improbable as, let's be honest, certain things you'd see on [i]CSI[/i].
I also have to say, though Montalban's character acts with single-minded obsession through the third act, he is still treated with general dignity. He is interviewing a suspect who is rather snobbish about the fact that his family have been in the United States since before there was a country to be from. He says that he's used to people showing him respect. Montalban replies that he is, too, and his family has been here less than a century. He is able to hold his own intellectually, following the esoterica of "legal medicine," I believe they call it, better than I suspect a lot of the audience could. Yes, he's obsessive at the end, and yes, he's a little less than sensitive. He really is an antihero. On the other hand, he isn't entirely a bad person. He's just leaning a little heavily on some shaky evidence, determined to find the information which will convict Shanway, not necessarily the information which would solve the case.