OK, this one is simple.
If you've read Empire of the Wheel 2: Friends From Sonora then you are up to speed on the whole scenario I propose regarding the legendary and notorious Butch Cassidy and The Sundance Kid and their companion Etta Place. You already know that I have proposed Etta Place was a secular nun for an Episcopal order, likely one based in New York with posts in Texas, and was working undercover as a field asset -- not an agent -- for the US Secret Service. I also argue that she was assassinated in San Bernardino, California, on 18 Nov 1915 while probably still working for the Secret Service. The details and analysis are in the book, along with my theory about Butch and Sundance and their South American adventure. Again, refer to the book.
The question I am answering here is: Why did the Pinkerton men never catch Butch and Sundance?
Here's your answer: Because they were never supposed to catch them.
Look at the history: Alan Pinkerton founded a spy network for Abraham Lincoln during the US Civil War. That very network subsequently became the US Secret Service. Pinkerton founded and his sons went on to run The Pinkerton Detective Agency. My book already presents the fact that William Pinkerton, who was in charge of western operations during the time of Butch and Sundance's activity in the US, was known to have been a patron of the very same saloon in which Butch and the gang partied and were supposed to have met Etta Place. The book provides the details on that also. Essentially, I argue that William Pinkerton was generally aware that Etta was affiliated with the Secret Service and the implication is that the Pinkertons stood down. Remember, the railroads were very lucrative clientele for the Pinkerton agency and, as laid out in my book, there may have been railroad involvement in Butch and Sundance's activity. Pinkerton had more than one good reason to play ball if Etta and the boys were working undercover and I've already covered that this would account for them never being caught while in the US. But why were they not captured in South America?
DiMaio was the Pinkerton man in South America. He 'happened to be in Argentina' when Butch and Sundance and Etta headed down that way. In spite of the trio establishing and living on a ranch and interacting with people daily, essentially being sitting ducks, DiMaio was never able to make any headway in confronting them.It seemed his approach was to hang back. Hmm. Even after Butch and Sundance were alleged to be robbing banks and such down there, DiMaio's efforts came to nothing. Even when Sundance and Etta were going back and forth between South America and the US, DiMaio didn't even catch them in that process, which should have been relatively easy. This does not make sense to me and I've heard the debate. DiMaio should have caught them.
Unless he was not supposed to.
And why would DiMaio be instructed not to catch them?
DiMaio's career with Pinkerton got its start working against the Sicilian Mafia in the United States. His first big case was to work undercover in a prison in 1891, investigating leads associated with the assassination of the New Orleans' Chief of Police David Hennessey. It just so happens that DiMaio's cover was established and facilitated by the agency overseeing the case. This particular agency created DiMaio's cover among counterfeiters and agents of this organization made the fake arrest to place DiMaio in prison to get close to a Mafia suspect.
Now which agency worked counterfeit issues back then -- and still does?
The United States Secret Service. Yes, the Secret Service was the lead agency on the Hennessey murder case operation that inserted Frank DiMaio into a prison under cover as a counterfeiter. DiMaio was an operative under the control of the Secret Service during the prison operation. DiMaio's career is hallmarked by his exemplary work investigating the Mafia in the US in the late 19th and early 20th Centuries. During this time, the Secret Service was the federal agency. There was no FBI then. The Secret Service was the lead agency on counterfeiting and all national security matters as well as criminal enterprises of immigrant communities, the Italian Mafia being the primary concern in that regard. Essentially, everything Frank DiMaio did most and best fell under the jurisdiction of the Secret Service. Therefore, it stands to reason that the Hennessey case prison operation might not have been the only time DiMaio operated under the supervision of the Secret Service, the federal agency with an intimate association to DiMaio's employers, the Pinkerton Agency.
Which brings us to South America. Frank DiMaio was the Pinkerton man assigned to pursue and report on Butch and Sundance and Etta in South America. If my speculation is correct that Etta Place was an operative for the Secret Service, then DiMaio may very well have been instructed to not make much of a real effort. In fact, it is quite possible that DiMaio could actually have been a support agent for Etta's assignment. If Frank DiMaio was an asset for the Secret Service, and there is documented fact to support this possibility, it explains why he was 'never able to catch up with them'.
In my opinion, Frank DiMaio's known history provides much to support my theory that Etta Place was indeed a Secret Service operative. I will add to this posting as I find more evidence.
American Mafia: A History Of Its Rise To Power by Thomas Reppetto, Henry Holt & Co, 2004
Spirit of Vengeance: Nativism and Louisiana Justice 1921-1924 by John V Baiamonte, Jr; Louisiana State University Press, 1986
American Mafia History, article on Frank DiMaio by Thomas Hunt, author of Deep Water: Joseph P. Macheca and the Birth of the American Mafia; http://mob-who.blogspot.com/2011/04/dimaio-francis-1864-1954-pinkertons.html
A conversation with my associate Rafe Marhefka