(August 5, 2008)—Law enforcement officials familiar with the case say Bruce Ivins borrowed freeze-drying equipment from a bioweapons lab that was used by scientists to convert wet anthrax spores into a powder.

The drying unit was not commonly used by researchers at the Fort Detrick, Maryland, lab where Ivins worked.

Officials who spoke on the condition that they not be identified say documents Ivins created during the check-out process and in his experiments are being mined for proof that he might have used it to powderize anthrax spores.

Ivins killed himself last week.

Court documents connected to the case could be released as early as Tuesday. The Justice Department is expected to decide soon whether to end the "Amerithrax" investigation by concluding Ivins acted alone in carrying out the attacks that killed five and sickened 17 in the weeks after the 9/11 attacks.