(BENTON, IL) — On Friday, 30 year old Adam M. Calvert, of Herrin, Illinois, has pled guilty to a one-count indictment charging conspiracy to distribute heroin. The offense occurred between 2012 and January 2014, in Williamson and Jackson Counties. Evidence at the plea hearing established that Calvert was involved with others in the distribution of heroin. On multiple occasions, Calvert sold heroin to a confidential source working for law enforcement. During the execution of a July 2013 search warrant at Calvert’s Herrin residence, officers located syringes, pre-recorded buy money, a digital scale, plastic baggies with white residue and numerous other drug-related items. During a later January 2014, arrest, officers located heroin in Calvert’s sock. At that time, officers again located digital scales, used syringes, and other drug-related items at Calvert’s residence. Calvert is currently being held without bond pending a May 13, 2015, sentencing hearing. At that time, Calvert faces up to 20 years in federal prison, to be followed by 3 years’ supervised release, and a fine of $1,000,000. The ongoing investigation is being conducted by the Southern Illinois Enforcement Group and the Drug Enforcement Administration. The Williamson County State’s Attorney’s Office assisted in the investigation. The case is assigned to Assistant United States Attorney Amanda A. Robertson for prosecution.