Anoka County prosecutors have charged former Chisago County sheriff Richard Duncan with stalking, threats of violence and misconduct of a public officer. According to the criminal complaint, Duncan was actually the writer of a series of what he claimed were “blackmail” letters from someone called “Control Freak,” trying to get him and a female co-worker to attend a training session in Bemidji and stay overnight in a hotel room. The stalking charge carries a penalty of up to 10 years in prison.