A teenager who opened fire with a 9 mm pistol in his Nashville high school cafeteria fired a total of 10 shots within 17 seconds of entering the room, according to police.

An AI gun detection system installed in a Nashville, Tennessee high school couldn’t spot the gun a 17-year-old used to fatally shoot another student and himself earlier this week, according to district officials.

The teenager who fatally shot a student at a high school in Nashville, Tennessee, livestreamed part of the incident, according to the platform he used, and he was influenced by internet content that authorities described Thursday as “harmful and objectionable.