The investigation into why a Nashville high school student fatally shot a classmate before killing himself has centered on his online writings.

The shooter was “significantly influenced by web-based material, especially that found on non-traditional sites that most would find harmful and objectionable,” police said.

One student is dead and another is wounded after a third student opened fire with a pistol Wednesday at Antioch High School in Nashville, Tennessee, police said. The 17-year-old shooter then shot himself and died,