A Livermore, Calif., man who was convicted in 1999 of threatening to release anthrax in an Oakland federal building, has been indicted by a federal grand jury on charges of making another threat, according to court records.
The indictment, which was handed down Thursday by a San Francisco federal grand jury, revealed that the threats were mailed to an undisclosed party by Charles Redden on June 16 and again on January 14.
The indictment, which accuses Redden of two counts of mailing threatening communications, released no further details.
In 2002, Redden was convicted of making a biological weapons threat and sentenced to five years in federal prison. Redden had faced a maximum life term.
Prosecutors in the earlier case said that Redden telephoned the Oakland court clerk's office in January 1999 from the Alameda County Jail, warning that he planned to spread anthrax in the federal building's air-conditioning system.
U.S. agencies are estimated to have spent more than $50 billion increasing the strength of biological defense in the years since the September 2001 anthrax letter attacks that killed five people and shuttered Congress and the Supreme Court, crippling the mail service for months.
Since the start of 2007, the FBI has investigated more than 1,000 so-called white powder events. To date, no other anthrax attacks have occurred.