As facts become known, I will post here some answers to that question.
Some news reports and commentary:
https://www.thedailybeast.com/nashville-covenant-school-shooting-suspect-identified-as-audrey-hale
https://www.thedailybeast.com/nashville-school-shooting-audrey-hale-messaged-friend-minutes-before-massacre
https://theconservativetreehouse.com/blog/2023/03/28/nashville-transgender-killer-was-likely-motivated-by-resentment-against-christians/
"Stoke the fires of rage and resentment long enough,
while justifying violence as an excusable outcome caused by wounded sensibilities and uncomfortable words,
and the Nashville result is what happens."
https://nypost.com/2023/03/28/audrey-hales-mom-i-think-i-lost-my-daughter-today/
" “What she did was unforgivable, but when I knew her, she was a sweet and funny girl,”
one friend told DailyMail.com, saying they
“thought for sure it was a mistake at first”
when Hale was identified as the child-killer. "
Metro Nashville Police Department video showing their response
https://youtu.be/Ue2tZa4hT0c
https://www.foxnews.com/opinion/tucker-carlson-trans-movement-targeting-christians
Nashville Covenant School head of school hailed as hero in wake of shooting: 'She protected her children'
https://www.foxnews.com/us/nashville-covenant-school-headmaster-hailed-hero-wake-shooting-she-protected-children