The Carson City Sheriff's Office says John Aston died in prison early Thursday morning in the infirmary in the Northern Nevada Correctional Center.

Aston was facing trial next year for threatening Carson City Judge John Tatro and his family for several years before being arrested in 2016. 

He was a sentence for illegal firearm possession. 

Carson Sheriff Ken Furlong says Aston was "in dire health" when police arrested him last year and had "substantial aging issues."

The exact cause of death is under investigation.