The teen was found dead in a rolled-up gym mat at a southern Georgia high school in January. Authorities say he was suffocated in the mat while looking for a sneaker. His family says he was murdered. And they believe the surveillance video, now being withheld, will tell the true story. “There is one eyewitness that we know is available,” attorney Chevene B. King Jr. said yesterday. “For some unknown reason, this tape has been withheld.” The teen's relatives are not the only ones searching for answers. Federal authorities are looking into the case, too.