Hi all. I'm brand new to this forum, and have only spent about a month learning about Cooper, though I'm a veteran of several other rabbit holes, true crime and otherwise. As my screen name indicates, my expertise is in books. I'm an academic librarian, long-time bookseller, former English major, and independent researcher. The contention that the phrase "negotiable American currency" indicates that Cooper was not from the U.S. does not ring true to me. Not to pick on the fine folks at the Citizen Sleuths website, but their statement is a good example. They say, "Since no American citizen would use those terms, it suggests that Cooper was not originally from this country." I did some quick checking in Google Books and the Internet Archive, and came up with three instances of the phrase, and three more of the phrase "negotiable U.S. currency." All are from U.S. publications, four of the six are clearly American authors, and the uses range in publication date from 1963 to 2002. I list them below. I have screen shots of all, if anyone wants context. For now, I'll just attach the first one with an unidentified author.
Unknown author, Car Life Magazine, 1963, uses “negotiable American currency.”
Philbrooke Paine, born 1910, journalist from New Hampshire, author of Squarely Behind the Beavers, 1963, page 29, uses “negotiable American currency.”
John Reese, born 1910 in Nebraska, western and crime writer, “The World’s Second Oldest Profession,” Mike Shayne Mystery Magazine Annual 1972, page 57, uses “negotiable American currency.”
Veronica Geng, born 1941 in Atlanta, raised in Philadelphia, acclaimed editor and writer for publications such as the New Yorker, New York Times, Love Trouble: New and Collected Work, 1999, page 198, uses “negotiable U.S. currency.”
David McClintick, born 1940, raised in Kansas and Montana, Swordfish : a true story of ambition, savagery, and betrayal, 1993, page 216, uses “negotiable U.S. currency.”
The Currency Dealer Newsletter: October 2002, page 110, published in California, uses “negotiable U.S. currency.”