No sh*t, Sherlock

"No sh*t, Sherlock" - who coined that?
Five years ago I am pretty sure I had never heard it; now I sometimes find myself saying it, and I have no idea where or when I first encountered it.

I recall an American friend (from Queens, New York) using it in the early 1970s.

1970s, originally U.S., ext. of "No, ****!" (late 19c). Sherlock is a pun on Holmes!, which itself puns on "homes"; plus ironic use of the fictional detective SHERLOCK Holmes. From Cassell's Dictionary of Slang by Jonathon Green (Wellington House, London, 1998). Page 847. I'm not sure what all that means -- the homes part.

Like ESC, I don't understand what Jonathan Green may have meant. I used to hear the phrase used pretty often, long before 1970, probably in the 1940s. My recollection is that it was then used as a longer version of today's "Duh!"--that is, as a sarcastic way of saying, "So your powers of deduction have led you to that amazing conclusion?" whereas "Duh!" gets us right to "Obviously."
SS

Homes = Homie; homeboy; home dawg; home slice. I don't really get the connection either unless "homes" changed to "Sherlock" when the phrase jumped from the ghetto to the suburbs.