BOISE, Idaho (AP) — A man who received a 10-year sentence after causing an anthrax scare in Boise has been convicted of new crimes after his release from prison.

A southwest Idaho jury on Thursday convicted 48-year-old Sandy Nanney of arson and malicious injury to property. In 2003, Nanney sent 35 scare letters containing a white powder he claimed was anthrax. He was caught when he handed one to an Ada County marshal and confessed.

He was granted parole in June 2013. Prosecutors say that five months later he went on a vandalism spree in Boise, throwing rocks through windows and starting a fire.  Nanney is scheduled to be sentenced Sept. 9. He could get life in prison because he is a repeat offender.