In this screen grab from surveillance video from the Metropolitan Nashville Police Department, Audrey Hale, points an assault-style weapon inside The Covenant School.

Video. Watch: Nashville polices release video of armed suspect in school

 A former student shot through the doors of a Christian elementary school in Nashville, Tennessee and killed three children and three adults after planning the massacre by drawing out a detailed map and conducting surveillance of the building, police said.

 A former student shot through the doors of a Christian elementary school in Nashville, Tennessee and killed three children and three adults after planning the massacre by drawing out a detailed map and conducting surveillance of the building, police said.

The massacre at The Covenant School in Nashville was the latest in a series of mass shootings in a country that has grown increasingly unnerved by bloodshed in schools.

The victims included three 9-year-old children, the school’s top administrator, a substitute teacher and a custodian. Amid the chaos a familiar ritual played out: Panicked parents rushed to the school to see if their children were safe and tearfully hugged their kids, and a stunned community planned vigils for the victims.

Video released by the Metro Nashville Police Department on Monday night shows a person walking through the school hallways, going through several different doors and pointing a gun.

Police gave unclear information on the gender of the shooter. For hours, police identified the shooter as a 28-year-old woman and eventually identified the person as Audrey Hale. Then at a late afternoon press conference, the police chief said that Hale was transgender. After the news conference, police spokesperson Don Aaron declined to elaborate on how Hale currently identified.

Watch more.