John Evans of course is the pseudonym for Howard Browne and he created on the the best PIs in literature: Paul Pine. Pine is more than your girls, guns, and guts PI -- he actually cares about the people he gets involved with and the reader cares about him. He eats at the drugstore lunch counters, fires up the smokes and takes his lumps along the way.
"So Dark for April" came out in Manhunt in 1953. Browne published three Paul Pine novels before that: Halo in Blood (1946), Halo for Satan (1947), Halo in Brass. (1949) After the short story in Manhunt by published, Browne wrote the forth and last Pine novel The Taste of Ashes (1957). All four novels are highly recommended.
As for "So Dark for April", Pine has to find a murderer to clear his name as the suspect. The short story is a gem that reads like one of Browne's Pine novels. I found it more hardboiled than the novels and I enjoyed that. As Pine finishes the case, the reader wonders why people do these things and risk losing so much. Few short stories can capture this. Manhunt had many great short stories throughout its publishing years and "So Dark for April" is one of the best.
I'm not one to recommend what others may want to read, but the Paul Pine series is excellent, classic noir literature. There is a line in Halo for Satan that sticks with me, "Whoever was behind the blackjack must have been an old hand at the game. I never heard a thing."
Well Mr. Browne I heard -loud and clear.....