Jay Stewart Devaughn, 41, is accused of sending powder to several offices, including those of U.S. Senators Mark Udall (D-Colorado) and Michael Bennet (D-Colorado) and the offices of U.S. Representatives Mike Coffman (R-Colorado) and Diana DeGette (D-Colorado).
Devaughn was scheduled to have a change of plea hearing Thursday, but prosecutors and Devaughn's attorney have asked to delay that hearing for a month.
Devaughn has pleaded not guilty to eight federal charges from the federal court in Colorado, including mailing threatening communications and false information and hoaxes. Prosecutors in the Northern District of Alabama federal courts have charged him with one count of false information and hoaxes.
The cases have been combined in the U.S. District Court in Colorado.
"He is expected to plead guilty," U.S. Attorney spokesman Jeff Dorschner confirmed. "Details of the plea agreement will not be made available until after the change of plea hearing," Dorschner said.
9Wants to Know has learned the mailings happened during 2009. Officials will not say if the mailings were sent to Sen. Udall and Sen. Bennet's local or Washington D.C. offices.
Coffman spokesman Nat Sillin said the powder came in an envelope mailed to the Congressman's Lone Tree office. The envelope arrived Nov. 24, 2009.
Postal inspectors determined the powder was not dangerous, Sillin said.
9Wants to Know has also learned other leaders may have been targeted by the mailings.
Court records show in January, Birmingham FBI agents investigated 12 white powder letters mailed from Alabama to the offices of Alabama senators and representatives in Washington, DC.
Authorities also say Devaughn left several threatening voicemail messages for people in the Denver Metro area that said, "How do you want to die," and "I'm going to blow both of your brains out."
They say he targeted his high school trigonometry teacher.
They also say he used those victims' names on the return addresses for several packages containing white powder that he mailed to lawmakers.
Devaughn worked at the Community College of Aurora as director of library services until resigning after his arrest earlier this year. He was voted the administrator of the year in 2009.
If you know more information about this case, e-mail Jace Larson at firstname.lastname@example.org or call 303-871-1432. Follow Jace Larson on Twitter: jacelarson.
(KUSA-TV © 2010 Multimedia Holdings Corporation)