Law enforcement officials seeking a motive for a shooting at Nashville’s Antioch High School on Wednesday morning are examining alarming social media posts and writings tied to a teenager police say shot and killed a 16-year-old girl.

A month after a student opened fire at Abundant Life Christian School, another killed a classmate at Antioch High School. Both were active in an internet subculture that glorifies mass shooters and encourages young people to commit attacks.

A 17-year-old boy who opened fire in his Nashville high school's cafeteria fired a total of 10 shots from a 9 mm pistol within 17 seconds of entering the room.