MUNCIE, Ind. (AP): The manager of two central Indiana convenience stores where authorities say synthetic drugs known commonly as bath salts were sold has pleaded guilty to criminal charges. Twenty-seven-year-old Harpreet Singh made the guilty plea to a felony charge of corrupt business influence during a Delaware County court hearing Monday. He was among eight people arrested in June 2012 after police raids of six convenience stores in Muncie and Yorktown.