The superintendent of a Wisconsin school district where a student shot his principal six years ago said the nation must confront what's causing school shootings.

Tom Andres leads the Weston School District in Cazenovia. The district was rocked in 2006 when 15-year-old Eric Hainstock came to school with guns and shot Principal John Klang to death.

Andres said the Connecticut school shooting brought back terrible memories of that day. He said he doesn't understand why people need assault rifles but the country should attack the root of the problem and focus on helping troubled people.

He said guidance counselors and police liaison officers need to improve threat assessments. He added that parents need to more closely monitor their children's exposure to violence through video games and other media.