Question: The Adventure of the Red Widow, is a murder mystery by Adrian Conan Doyle, about what fictional private detective?

Context paragraphs:
The Adventure of the Dark Angels: The Adventure of the Dark Angels is a Sherlock Holmes murder mystery by Adrian Conan Doyle.  The story was published in the 1954 collection, "The Exploits of Sherlock Holmes".

Sherlock Holmes: Sherlock Holmes ( ) is a fictional private detective created by British author Sir Arthur Conan Doyle.  Known as a "consulting detective" in the stories, Holmes is known for his proficiency with observation, forensic science, and logical reasoning that borders on the fantastic, which he employs when investigating cases for a wide variety of clients, including Scotland Yard.

The Adventure of Foulkes Rath: The Adventure of Foulkes Rath is a Sherlock Holmes murder mystery by Adrian Conan Doyle.  The story was published in the 1954 collection, The Exploits of Sherlock Holmes.

The Canary Trainer: The Canary Trainer: From the Memoirs of John H. Watson is a 1993 Sherlock Holmes pastiche by Nicholas Meyer.  Like "The Seven Percent Solution" and "The West End Horror", "The Canary Trainer" was published as a "lost manuscript" of the late Dr. John H. Watson.  In "The Adventure of Black Peter", an original Arthur Conan Doyle Holmes story from 1904, Watson mentions that his companion recently arrested "Wilson, the notorious canary-trainer, which removed a plague-spot from the East-End of London."  This Wilson (who figures prominently in the Adrian Conan Doyle pastiche "The Adventure of the Deptford Horror") is not related to the eponymous character of Meyer's novel.  Meyer's "trainer" is Erik, the principal figure of Gaston Leroux's 1910 novel "The Phantom of the Opera".  It is from this unchronicled tale that The Notorious Canary Trainers (a Sherlockian scion in Madison, Wisconsin, founded in 1969) take their name.

The Adventure of the Red Widow: The Adventure of the Red Widow is a short Sherlock Holmes murder mystery by Adrian Conan Doyle.  The story was published in the 1954 collection, "The Exploits of Sherlock Holmes".

Paul Drake (character): Paul Drake is a fictional private detective in the "Perry Mason" series of murder mystery novels by Erle Stanley Gardner.  Drake is described as tall and slouching, frequently wearing an expression of droll humor.  He is friend and right-hand man to Mason, a highly successful criminal defense lawyer in Los Angeles.

The Adventure of the Abbas Ruby: "The Adventure of the Abbas Ruby" is a Sherlock Holmes mystery by Adrian Conan Doyle, the youngest son of Arthur Conan Doyle, the Sherlock Holmes creator.  The story was published in the 1954 collection, "The Exploits of Sherlock Holmes".

The Adventure of the Black Baronet: The Adventure of the Black Baronet is a Sherlock Holmes murder mystery written by Adrian Conan Doyle.  The story was published in the 1954 collection, "The Exploits of Sherlock Holmes", a joint enterprise of John Dickson Carr and Adrian Conan Doyle.

The Adventure of the Sealed Room: The Adventure of the Sealed Room is a Sherlock Holmes murder mystery by Adrian Conan Doyle.  The story was published in the 1954 collection, "The Exploits of Sherlock Holmes", a joint enterprise of Adrian Conan Doyle and John Dickson Carr.

The Adventure of the Gold Hunter: The Adventure of the Gold Hunter is a Sherlock Holmes murder mystery by Adrian Conan Doyle and John Dickson Carr.  The story was published in the 1954 collection, The Exploits of Sherlock Holmes.

Supporting paragraphs: The Adventure of the Red Widow Sherlock Holmes
Answer: Sherlock Holmes