The shooter, identified as former student Audrey Hale (28)

The 28-year-old who killed three children and three adults at a Christian school in Nashville last week fired 152 rounds 

Nashville police said Monday, adding that while they have yet to determine a motive, the shooter planned the attack “over a period of months” and studied other mass murderers. 

Two officers opened fire – a moment captured in bodycam footage later released by police – and killed Hale at 10:27 a.m. 

LIVE FOOTAGE :Audrey Hale Entering School

Evelyn Dieckhaus, William Kinney and Hallie Scruggs, all 9 years old, were killed in the massacre, as well as school custodian Mike Hill, 61, substitute teacher Cynthia Peak, 61, and Katherine Koonce, 60, who was head of the school.