"It Raises an Interesting Question: Is It Possible To Change the Future?"

"Cronus of the D.F.C."
(a.k.a. "D.F.C.").
By Lloyd Biggle, Jr. (1923-2002).
Illustration by Paul Orban.
First appearance: Worlds of IF, February 1957.
Reprinted as "D.F.C." (HERE).
Short story (14 pages).
Online at Archive.org (HERE).

     "Maybe I didn't make myself clear. We saw the holdups on that screen but we couldn't prevent a single one."

You would think that being able to view yet-to-happen events would be a huge advantage to law enforcement, making "crime prevention" a literal reality. Nonetheless, when a young detective falls in love with a woman he's convinced is going to die soon, every time he makes a move it becomes more and more obvious that he won't be able to do anything about it . . .

Major characters:
~ Detective Jim Forsdon (narrator):
  "He lunged at me like a pile driver, and forced me back towards the open window. I got my gun out, and he just casually knocked it out of my hand."
~ Captain Marks (unofficially, "the Old Man"):
  "You looked at him and wondered how he'd ever gotten on the force in the first place, until you saw his eyes. I'd never felt comfortable in his presence."
~ Dr. Howard F. Walker:
  ". . . we can't get that kind of support by predicting a few piddling holdups. But a murder, now—that would make someone sit up and take notice."
~ Stella Emerson:
  "Then I dispensed with the handshaking. She clung to me, and it might have been her first kiss. In fact, it was."
~ Mike Gregory:
  "He's not a criminal—but he is a potential criminal, and he doesn't know that."

Resources:
- Philip K. Dick's novelette with a very similar theme of preventing crime before it happens ("The Minority Report," Fantastic Universe, January 1956, online HERE, go to text page 4; movie version, 2002; and a TV series, 2015), was published a year earlier than "Cronus of the D.F.C." If you've already read Dick's story or have seen the movie/series, then you may (or may not) benefit from the Wikipedia articles (HERE; SPOILERS), (HERE; SPOILERS), and (HERE; SPOILERS).

- For decades starting in 1956, Lloyd Biggle was a steady source of entertaining SFF and mystery fiction, but he had other interests and talents as well; see Wikipedia (HERE), the SFWA (HERE), the SFE (HERE), and the ISFDb (HERE).

- Biggle wrote science fiction mysteries featuring Jan Darzek, whom the SFE characterizes as

   ". . . a late-twentieth-century private eye who becomes involved in adventures made possible by matter transmission, from investigating aliens sabotaging Earth's matter transmitters to chairing the Council of Supreme, which itself governs the home galaxy; by the third volume he is pitted against the inimical Udef, a Dark Force destroying civilization after civilization in the Smaller Magellanic Cloud."

The Jan Darzek books:
  (1) All the Colors of Darkness (1963)

  (2) Watchers of the Dark (1966)

  (3) This Darkening Universe (1975)

  (4) Silence Is Deadly (Worlds of IF, October 1957; expanded and revised in 1977)

  (5) The Whirligig of Time (1979).

- Biggle also wrote straight mysteries starring several of his own creations and one you've almost certainly heard of:
A. Grandfather Rastin:
   (1) "The Face Is Familiar" (a.k.a. "The Greatest Robbery on Earth"), AHMM, August 1957
   (2) "A Case of Heredity," EQMM, June 1959
   (3) "Grandfather and the Gentle Swindler," EQMM, February 1960
   (4) "Grandfather Predicts a Murder" (a.k.a. "The Lesser Thing"), EQMM, August 1960
   (5) "Grandfather and the Great Horseshoe Mystery" (a.k.a. "The Great Horseshoe Mystery"), EQMM, April 1962 (online HERE; go to text page 86)
   (6) "Have You a Fortune in Your Attic?" (a.k.a. "The Fabulous Fiddle"), EQMM, May 1963
   (7) "The Great Alma Mater Mystery" (a.k.a. "The Unmurdered Professor"), EQMM, November 1964
   (8) "Grandfather and the Labor Day Mystery" (a.k.a. "The Pair of Knaves"), EQMM, October 1965 (online HERE; go to text page 134)
   (9) "Grandfather and the Phantom Thief" (a.k.a. "The Phantom Thief"), EQMM, May 1968 (online HERE; go to text page 100)
   (10) "Grandfather and the Automation Mystery" (a.k.a. "The Automation Mystery"), EQMM, August 1969 (online HERE; go to text page 73)
   (11) "Grandfather and the Right Question" (a.k.a. "The Unasked Question"), EQMM, October 1971
   (12) "Grandfather and the Little Bone" (a.k.a. "The Mother Goose Murder"), EQMM, January 1972 (online HERE; go to text page 118)
   (13) "The Knave of Hearts" (a.k.a. "A Matter of Friendship"), EQMM, November 1998       (FictionMags data).
   These were collected by Crippen & Landru as:
   ~ The Grandfather Rastin Mysteries (2007)

B. The Fletcher and Lambert books:
   (1) Interface for Murder (1987)

   (2) A Hazard of Losers (1991)

   (3) Where Dead Soldiers Walk (1994)

   (4) Murder Jambalaya (2012).
C. Sherlock Holmes novels:
   (1) The Quallsford Inheritance (1986)

   (2) The Glendower Conspiracy: A Memoir of Sherlock Holmes: From the Papers of Edward Porter Jones, His Late Assistant (1990).

D. A non-series book completed by Kenneth Lloyd Biggle:
   Murder Applied For: A Classic Crime Mystery (2013)

E. Stories featuring Lady Sara Varnley:
   (1) "The Case of the Headless Witness," AHMM, November 1999
   (2) "The Case of the London Safari," AHMM, June 2001
   (3) "The Case of the Wolf with Two Tales," AHMM, April 2002
   (4) "The Case of the Fractured Puzzle," AHMM, September 2002
   (5) "The Case of the Sickley Mansion," AHMM, July/August 2003
   (6) "The Case of the Chinese Santa Claus," AHMM, January/February 2004
   (7) The Case of the Unrepentant Ghost," AHMM, September 2006 (FictionMags data).

The bottom line:
   The Moving Finger writes; and, having writ,
   Moves on: nor all your Piety nor Wit
   Shall lure it back to cancel half a Line,
   Nor all your Tears wash out a Word of it.
     — Omar Khayyam (via Edward Fitzgerald)
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