MINNEAPOLIS (AP) – A Minnesota head shop owner has been convicted of almost all counts against him in a closely watched federal case involving the sale of synthetic drugs.  The jury in Minneapolis found Jim Carlson guilty of 51 of 55 counts. The complex indictment included multiple charges of receiving and selling misbranded drugs.  Carlson operated a Duluth head shop called Last Place on Earth. He didn’t deny selling synthetics, but argued that he did nothing illegal.  Carlson’s girlfriend was convicted of four counts, and his son was convicted on two of four counts.  The trial was seen as one of the first major tests in federal court of how effectively authorities can combat synthetic drugs.