The Fermilab letter was originally assumed to be associated with neutrinos due to time proximity with the 20th Anniversary of SN1987A, and the letters mention of Frank Shoemaker, who worked with neutrino detectors. Confirmation has been found as time stamps in section 2.
http://www.scribd.com/doc/34230168/Fermi06222010
https://sites.google.com/site/sfcanalysis/