The transgender shooter's manifesto will be released publicly, but only after the FBI has combed through it to build a psychological profile of the killer.

28-year-old Audrey Hale was shot dead by police after killing three children and three adults at The Covenant School, a private Christian school for students aged three to 11.

Authorities say Hale deliberately targeted the school after considering but then rejecting two other public school targets because they had better security.

Police initially said Hale's transgender identity was a factor in motivating her rampage, but it seemed the manifesto she left might remain secret after lobbying from LGBT groups.

However, Nashville Council Member Robert Swope told the New York Post that the manifesto will be released publicly after all.

"The manifesto is going to be released. It's just a matter of when. There are some incredibly brilliant psychological minds and psychological analysts combing through her entire life," said Swope.