Authorities are examining “very concerning online writings and social media posts” connected to the shooter who killed a female student and wounded another student in a Nashville high school cafeteria.

The investigation into why a Nashville high school student fatally shot a classmate before killing himself has centered on his online writings, which authorities describe as concerning warning signs.

Police say the gun used in the Nashville school shooting was purchased in Arizona as detectives piece together why the high school student fatally shot a classmate before killing himself