Question: Ellery Queen and William Kennedy, have which occupation in common?

Context articles: Enemy Agents Meet Ellery Queen
Amateur in Violence
Ellery Queen (house name)
William Kennedy (author)
The President of the United States, Detective
Ellery Queen's Mystery Magazine
The Egyptian Cross Mystery
The Adventures of Ellery Queen
Ellery Queen (TV series)
Ellery Queen

Enemy Agents Meet Ellery Queen is a 1942 black-and-white thriller film, directed by James P. Hogan and written by Ellery Queen, the duo of Manfred Lee and Frederic Dannay.
Amateur in Violence is a collection of mystery stories by the prominent British thriller writer Michael Gilbert, published in the United States in 1973 by Davis Publications, a publishing house for magazines, but not in England.
 Gilbert, who was appointed CBE in 1980, was a founder-member of the British Crime Writers' Association.
 The Mystery Writers of America named him a Grand Master in 1988 and in 1990 he was presented Bouchercon's Lifetime Achievement Award.
 The book is edited, and has an introduction, by Ellery Queen, the founder and long-term editor of Ellery Queen's Mystery Magazine.
 It contains 10 stories and a short novel that had been previously uncollected in the United States.
 Some of them feature characters who have figured in other novels and short stories by Gilbert.
 Three stories feature Inspector Hazlerigg and four Inspector Petrella.
 The short novel, "Stay of Execution", had previously given its name to the title of a collection published in England in 1971.
Ellery Queen was the pen name for two cousins, Frederic Dannay and Manfred Bennington Lee, who wrote novels and short stories about a fictional detective character named Ellery Queen.
 At various points in their history, the cousins allowed the name of Ellery Queen to be used as a house name; novels written by other writers were published under that name.
 The cousins also wrote four novels that were published under the name "Barnaby Ross" and they later allowed that name to be used as a house name.
 Several of the main series novels were also ghost-written, but those were controlled and edited by the cousins.
William Joseph Kennedy (born January 16, 1928) is an American writer and journalist born and raised in Albany, New York, the son of William J. Kennedy and to Mary E. McDonald.
 Kennedy was raised a Catholic.
 Many of his novels feature the interactions of members of the fictional Irish-American Phelan family and make use of incidents of Albany's history and the supernatural.
 Kennedy's works include "The Ink Truck" (1969), "Legs" (1975), "Billy Phelan's Greatest Game" (1978), "Ironweed" (1983, winner of the 1984 Pulitzer Prize for Fiction; movie, 1987), and "Roscoe" (2002).
 In 2011, he published "Changó's Beads and Two-Tone Shoes", which one reviewer called a book "written with such brio and encompassing humanity that it may well deserve to be called the best of the bunch".
The President of the United States, Detective is a science fiction/mystery short story by H. F. Heard.
 It was originally published in "Ellery Queen's Mystery Magazine" in March 1947, and subsequently republished in "Ellery Queen's Mystery Magazine" in April 1969 and February 1991, in the 1949 anthology "The Queen's Awards", and in the 1975 anthology "Ellery Queen's The Golden 13"; as well, an extended version, named "The Thaw Plan", was published in Heard's 1948 collection "The Lost Cavern and Other Stories of the Fantastic".
Ellery Queen's Mystery Magazine is an American digest size fiction magazine specializing in crime fiction, particularly detective fiction, and mystery fiction.
 Launched in fall 1941 by Mercury Press, EQMM is named after the fictitious author Ellery Queen, who wrote novels and short stories about a fictional detective named Ellery Queen.
The Egyptian Cross Mystery is a novel that was written in 1932 by Ellery Queen.
 It is the fifth of the Ellery Queen mysteries.
The Adventures of Ellery Queen is the title of a radio series and four separate television series made from the 1950s through the 1970s.
 They were based on the fictional detective and pseudonymous writer Ellery Queen and the cases he solved with his father, Inspector Richard Queen.
Ellery Queen is an American TV series featuring the titular fictional sleuth.
 Starring Jim Hutton as Ellery Queen, David Wayne as his father, Inspector Richard Queen, and Tom Reese as Sgt. Velie, it aired on NBC during the 1975–76 television season.
 It was created by the writing/producing team of Richard Levinson and William Link.
 The title character investigates a murder in each episode, and the series uses some of the same dramatic devices found in the early Queen novels and radio shows.
Daniel Nathan, professionally known as Frederic Dannay (October 20, 1905 – September 3, 1982), and Emanuel Benjamin Lepofsky, professionally known as Manfred Bennington Lee (January 11, 1905 – April 3, 1971), were American cousins from Brooklyn, New York, who wrote, edited, and anthologized detective fiction under the pseudonym of Ellery Queen.
 The writers' main fictional character, whom they also named Ellery Queen, is a mystery writer and amateur detective who helps his father, Richard Queen, a New York City police inspector, solve baffling murders.