The FBI has disclosed two threatening letters from a mysterious source that could shed light on who might have been responsible for mailing the deadly poison ricin to a prominent senator earlier this year - as well as an attempt to send it to the White House last year.
The FBI says two letters received at government postal facilities last October both contained ricin and threatened more attacks if new regulations requiring truck drivers to rest for longer periods of time were not repealed.
Both were signed by someone identified only as Fallen Angel. In one, the writer, who claimed, according to the FBI, to own a fleet of tanker trucks - threatened to produce large quantities of ricin if those federal regulations were not rolled back. A second letter, this one addressed to the White House but intercepted at a mail facility in Tennessee - threatened, "to turn Washington into a ghost town" - if the new rules took effect.
The FBI is making the letters public at the same time it is offering a $100,000 reward. Officials hope it will lead to the arrest of whoever tried to send ricin to the White House last year, as well as whoever succeeded in sending a small amount of the deadly substance to Senate Majority Leader Bill Frist's office earlier this year. There were no injuries, but Senate office buildings were shut for several days, in an incident that was a reminder of the still unsolved case of the anthrax spores mailed to Senator Tom Daschle in 2001.