Formal criminal charges were expected to be filed Wednesday against a 15-year-old student who shot dead one school administrator and seriously wounded two others in Jacksboro, Tennessee, in the U.S. south, DPA reported. The shooting, which occurred Tuesday, happened when educators were checking a report the boy was armed, according to officials quoted by the Knoxville News Sentinel daily newspaper online. The student, Kenny Bartley Jr., shot dead assistant principal Ken Bruce. "We'll make a determination on charges later, after we've gathered all the statements and the evidence," Campbell County Chief Deputy Charles Scott was quoted as saying by the newspaper. Classes would be closed for the rest of the week at the Campbell County Comprehensive High School after the shooting - the latest in a series of school attacks over the past decade in the U.S.