A former Pennington County prosecutor has pleaded guilty to felony drug charges.

Former Deputy State's Attorney Toby Karn as part of a plea agreement pleaded guilty to possessing anabolic steroids and conspiring to distribute more than a pound of marijuana.

The 37-year-old Karn faces up to 20 years in prison and $40,000 in fines when he is sentenced on January 8.

Karn was a prosecutor for Pennington County from May 2000 to December 2002.