Over the last forty years I've read all of the Mason novels at least once, and most several times. This is one of the very best!
It was written in 1951, during probably Gardner's strongest period, roughly 1939 - 1953. The earliest novels have a distinct "film noir" feel. By 1939, Gardner was transitioning into his mature period, when he (and Mason) mellowed a bit. Later, after the TV series became a huge hit, the novels became mechanical, the writing almost sterile, though the great plots remained.
This one takes place almost entirely in a little town next to a lake in the mountains. A murder occurs late one night at one of the cabins on the lake. The cabin is owned by the wealthy landowner of most of the lake area, Dexter Cushing, but is used mostly by his son Arthur for fun and amorous pursuits. It is early December, and a coating of hoar frost forms around midnight, just enough to hold some tracks until it melts during the next morning. Who made the tracks and when? Suspicion quickly falls on Belle Adrian, the mother of a young woman (Carlotta) who had had dinner at the cabin the night before, and apparently stayed too late for her own good.
The story has several of Gardner's recurring themes: the setting, a cabin high in the mountains a few hours drive from LA; a ne'er do well son of a wealthy older man; a basically good-hearted rural sheriff; an over-confident rural DA. Ne'er do well sons or stepsons occur frequently in the Mason novels, such as the Case of Black-eyed Blonde. The basic idea of a 'wolf' attacking a young woman who gets away, and then the wolf is murdered, occurs also in the Case of the Waylaid Wolf.
But this one is considerably better than the Waylaid Wolf (though that story is pretty good). This is definitely one of Gardner's best novels. Unlike some, it is not TOO complicated. The resolution is especially tight and logical. I can think of no objections to any part of the plot. Everything is there. Little clues are left for the reader. But can the reader tell the clues from the red herrings?
There is little use of Della. Perry does not skirt the edge of the law or mix up witnesses or guns, but there is a personal threat against him, in that the DA thinks he has improperly subpoened a witness who knows nothing of the case -- that's the "angry mourner." This makes for some great courtroom scenes.
No Lt. Tragg or Hamilton Burger. Good Paul Drake. Perry describes an interesting algorithm for checking a lot of license plates. The passage where the method is described is quoted in a famous computer science book.
There aren't very many suspects. The clients are sympathetic.
Highly recommended. This is definitely among the top five Perry Mason novels. Too bad it doesn't have Hamilton Burger in it!
PS: This story has a lot of similarities to the earlier Case of the Lazy Lover. They both involve the analysis of tracks. They both have a defendant whose daughter is involved. They both feature an older rich man who has had some shady deals and taken advantage of people. They both feature a second young woman who seems to be very sharp witted. However, the Lazy Lover is TOO compilicated and has people taking unreal actions. The Angry Mourner is better.
Belle Adrian, concerned mother of 21 year old
Carlotta Adrian, who doesn't need a chaperone.
Dexter Cushing, wealthy landowner.
Arthur Cushing, son of Dexter.
Sam Burris, long time resident of the lake side.
Mrs. Burris, his wife.
Harvey Delano, young lawyer and friend of Carlotta.
Sheriff Bert Elmore, competent, insistent.
District Attorney Darwin Hale, who's not going to be fooled by any city slicker lawyer.
C. Creston Ives, distinguished lawyer hired by Dexter Cushing.
Nora Fleming, the Cushing housekeeper.
Marion Keats, young woman, the "angry mourner."