The Diamond Ransom Murders

Originally published in 1934 "The Diamond Ransom Murders" is among one of the first police procedural novels. As with many modern stories of this genre, the reader is along for the ride with the main character, finding clues and figuring things out along the way.

The police of Los Angeles are puzzled by the disappearance of three prominent citizens. They are seen driving past a certain corner, and five minutes later their car is found standing empty near the middle of the block. The street is a busy one, but no one is found who has seen anything out of the ordinary. While Jerry Irish, the best detective on the Los Angeles force, is still wondering how to attack the problem, word comes to him that the Governor of California has been kidnapped out of his suite at a Los Angeles hotel. And all this is only the beginning. There are more, and worse, crimes to follow.
Jerry Irish, still in his twenties, is the top detective in the LAPD. He's smarter and more imaginative than his peers, has learned state-of-the-art crime-fighting techniques in Paris, and can rely on advice from his retired police-chief father, Dandy Jim Irish. Jerry has very little to work on in the way of clues-a tiny speck of green feather-a diagram which may or may not mean something. With the press clamoring for action, Jerry must try to figure out who's behind the crimes and what they plan to do next.