Ambrose Bierce, "My Favorite Murder" (1888) from Ambrose Bierce: The Devil’s Dictionary, Tales, & Memoirs:
After yesterday's uncertainty about how humor ages (poorly, usually), I'm presented today with a funny and weird Ambrose Bierce story--and usually we only think of Bierce as being weird.
When I was young and stole my sister's copy of Bierce's Can Such Things Be?, I remember laughing at some of the little touches Bierce put in his macabre tales. For instance, in "The Damned Thing," Bierce titles one of his sections "One Does Not Always Eat What Is On The Table"--because what's on the table is a dead man. So I know he can be funny, even when--or especially when--he's writing about death and destruction.
"My Favorite Murder" takes this connection between the macabre and the amusing and, as no kids say today, turns it up to 11. The bulk of the story is an artistic and at time geometric appreciation of how the narrator killed his uncle; this was accomplished by putting him in a sack, hanging the sack from a tree, and luring the uncle's own maladjusted ram into head-butting the uncle to death. So a lot of the humor in this bulk comes from the mismatch of topic (murder) and tone (artistic appreciation).
There's a few other layers in that murder-humor; for instance, the narrator joins a secret fraternity and discovers his uncle is one of the members and this means that his murder will also be a treason against the fraternity--and that makes it a good thing.
The whole piece is structured by that sort of reversal: now that the narrator has less reason to kill the uncle, he's even more excited to do it; once the narrator can prove how awful his uncle's murder is, he'll be let go; etc.
Which brings us to the frame story. Because the core of this is the evidence that the narrator gives to get out of his murder trial for killing his mother. As the narrator notes of his parents, skirting close to the classic definition of "chutzpah"--murdering your parents and then asking the court for mercy as an orphan--"one of whom Heaven has mercifully spared to comfort me in my later years."
In fact, while the core of this story is funny without necessarily carrying a message, the frame story paints the court system as completely ridiculous, with the defense attorney saying that the murder of his mother shows "tender forbearance and filial consideration for the feelings of the victim"--and then getting him off for just that reason. Let's remember Bierce's definition of "Lawyer" from The Devil's Dictionary: "One skilled in circumventing the law."