A Georgia sheriff has reopened an investigation into the 2013 death of a teenager whose body was found inside a rolled-up gym mat at his high school, saying he’s reviewing 17 boxes of evidence collected by federal agents that his office recently obtained from the U.S. Justice Department. Fellow students found the body of 17-year-old Kendrick Johnson in the gymnasium at Lowndes High School in Valdosta on Jan. 11, 2013. Johnson’s parents have insisted from the beginning that he was slain, and have long accused law enforcement and school officials of covering up the crime. One of the students accused by Johnson’s parents was away from school traveling to a sports tournament at the time Johnson died, according to the case file from the sheriff’s initial investigation. Paulk said he’s personally leading the new investigation, which will compare the federal agents’ findings with evidence the sheriff’s office gathered in 2013.