"Gold Digger," by Reavis Z. Wortham, in Bound by Mystery, edited by Diane D. DiBiase, Poisoned Pen Press, 2017.
Most
of this story takes place in May 1934, on the night Bonnie and Clyde
died, although that has nothing to do with the story. (Well, now that I
think of it, it might explain a bit of one character's motivation.
Subtle, that.) It's rural Texas and our narrator is a ten year old boy
at a barn dance, with no less than Bob Wills and his Texas Playboys
performing. He witnesses a murder, a pointless killing involving that
ancient cause of trouble, an older husband a younger wife.
Then
we jump to the same guy in World War II, and then many years later to
his old age. And only at that point does he, and do we, figure out
exactly what was going on back in 1934. I didn't see the twist coming
at all.