Seven students and their principal were killed on Wednesday when an 18-year-old gunman opened fire in Finland's Jokela High School. About a dozen people were injured as they fled the school. Following the rampage(凶暴な行為), the shooter, who has not yet been identified, turned his .22 caliber(口径)handgun on himself. A video titled "Jokela High School Massacre" was posted on YouTube shortly before the killings and shows a photograph of what appears to be Jokela High School and images of a young man holding a gun. Police are now investigating connections between the video and gunman.