"He Found His Heart Aching Curiously at Thought of How Discovery of the Killer Would Hurt Her"

"Too Well Remembered."
By Carrington Phelps (?-?).
First appearance: Collier's Weekly, July 28, 1928.
Short short short story (2 pages).
Online HERE.

"A secret-service man does a difficult job a little too well . . ."

Soldiers are expected to kill the enemy, not their buddies:

. . . Here four hundred men had been at rifle and machine-gun practice. Here in the cool of the shade some had loafed and rested between periods. And two had gone back into the undergrowth and one had killed the other. Shot him from behind. Blown out the front of his head. The shot hadn't been noticed because it had blended with the noise of the practice. And then the killer had eased himself back among his fellows—was mingling with them today, free and unmolested, safe—perhaps. He might have been one of those on guard when G. M. had passed the gate of the big camp—might be the orderly standing there a few paces to the rear.

For G. M. solving this case is hard enough, but it gets far worse when he falls in love . . .

Resources:
- We can't find anything about our author, but he did produce enough for a decent FictionMags listing HERE.

The bottom line: A really good detective never gets married.
— Raymond Chandler