Officials have determined that the suspicious white powder mailed to John McCain’s Denver campaign office along with a death threat is not anthrax. Experts say they’re not certain what the substance is, but they’re sure it’s not harmful.

The Secret Service has identified the person suspected of sending the Denver letter. The suspect, Marc Harold Ramsey, is an inmate at the Arapahoe Detention Center who has been incarcerated since September of 2007.

Ironically, the crimes that landed Ramsey in prison to begin with are felony menacing, harrasment, and second-degree assault on a police officer. Ramsey will likely now face federal felony charges relating to the fake anthrax letter and death threat.