This month’s pulp is written by Richard E. Wormser who was an American pulp writer who wrote fiction in just about all genres from the early 1930’s until his death in 1977. When the pulps died out in the 1940’s Wormser kept writing and to his credit has over 200 pulp stories including seventeen early Nick Carter stories and several award winning western novels and novelizations of movies and television shows. This story appeared in the 01 December, 1934, issue of Argosy and was also included in the first issue (1940) of the short run pulp title Foreign Legion Stories.
The story is an oft-repeated one that has the long arm of American law enforcement, in this case Detective Cafferty of New York, reaching into the Legion to solve a cold case mystery.
(Not my scan but thanks to the original scanner to put this out on the web whose name I do not know.)