A Kentucky prison inmate has pleaded guilty to mailing a threatening letter.
Twenty-nine-year-old Charles Harris pleaded guilty yesterday to mailing a letter containing a white powder with a message that included the word "anthrax" to the U.S. District Court Clerk's office.
Harris mailed the letter to the Louisville office nearly five years ago. At the time he was an inmate at Ky. State Penitentiary in Eddyville.
The U.S. Attorney's Office said the powder was tested and found not to be hazardous.