I went to the Minister of the Interior, Department of Immigration, and got an instruction sheet for obtaining a DNI. I'm retired and for me it was fairly clear, listing all the documents and fees required. Many of the instructions led me to sub-instructions.
IE: They sent me to the Consular Section of the American Embassy where I got instructions for "Obtaining A U.S. Good Conduct Certificate". One of its requirements was for me to be fingerprinted so I wandered around BsAs for awhile looking for an authorized fingerprinter. Finally I went to the police station across from the zoo. They did an old fashioned, ink, fingerprint which I sent to the FBI on April 24, 2013.
I was also fingerprinted, this time electronically, when I applied for the good conduct certificate of the local police.
I havent heard from the FBI yet.
I'm not surprised that many people are confused. It reminds me of a scavenger hunt. If I were a criminal I would have given up just bought a DNI.