A southwestern Illinois prison guard who worked a second job as an instructor for those arrested for driving under the influence has been charged with forgery.  The Belleville News-Democrat reports 42-year old Kevan Caliper was hit with felony forgery charges Saturday.  He allegedly signed documents for a defendant’s court-ordered treatment which hadn’t been completed.  Such documents are used to evaluate if a defendant is a public safety risk.  Caliper’s Belleville-based business is First Choice DUI Services and Evaluation.  Saint Clair County State’s Attorney Brendan Kelly says discrepancies in paperwork led the Illinois Attorney General’s office to investigate.  Caliper’s attorney James Stern says Caliper pleaded not guilty.  Caliper also works at Southwestern Illinois Correctional Center in Washington Park.  Corrections officials say there’ll be a hearing determining if Caliper will face suspension.