Officials at The Covenant School, the Nashville, Tennessee, Christian elementary school where a trans killer barged in on March 27 and gunned down three 9-year-olds and three adults, have filed to intervene in a lawsuit seeking the public disclosure of a manifesto the shooter left behind.

The National Police Association (NPA) and Tennessee-based private investigator Clata Brewer are suing city and county officials, demanding copies of Audrey Hale's writings, which were recovered from the killer's vehicle and home after the shooting.

A judge is expected to make a decision in June, according to the NPA. In addition to the manifesto, the NPA is also seeking copies of police communications related to the document.

The police group said The Covenant School is asking to protect floor plans of its facility and personnel information and that the NPA does not object. A judge has scheduled the next hearing for Thursday afternoon.

AUDREY HALE POLICE BODYCAMS RELEASED

Audrey Hale in tactical gear marauding through a school hallway

Covenant School shooter Audrey Hale, 28, is shown in a driver's license photo, inset, and on school surveillance video released by Nashville police. Hale killed three 9-year-olds and three adults at a private school linked to a church. (Metro Nashville Police Department)

The killer wrote a manifesto, kept journals and made hand-drawn maps and diagrams of the school, with possible entry points and illustrations that depicted a shooter wearing the same outfit that Hale wore on the day of the shooting, police said after responding officers killed the attacker.

Police previously released surveillance video that showed the heroics of responding police officers as they stormed the building and killed Hale in front of a second-story window, which is where the killer was shooting at police outside.

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According to its website, The Covenant School opened in 2001 as part of the Covenant Presbyterian Church and served children from pre-K through sixth grade.

Covenant Presbyterian Church security camera footage, released by Metro Nashville police, shows 28-year-old school shooter Audrey Hale.

Covenant Presbyterian Church security camera footage, released by Metro Nashville police, shows 28-year-old school shooter Audrey Hale. (Metro Nashville Police Department)

The child victims included the pastor's daughter, Hallie Scruggs, as well as Evelyn Dieckhaus and William Kinney. Police identified the adults as 60-year-old Head of School Katherine Koonce; Cynthia Peak, 61; and Mike Hill, 61.

NASHVILLE SCHOOL SHOOTING: OFFICERS WHO TOOK OUT COVENANT SHOOTER IDENTIFIED

Court records suggested Hale had no criminal history in Metro Nashville or Davidson County.

Police officers hold guns and walk though Covenant School

Bodycam footage shows Nashville Police Department officers responding to The Covenant School after 28-year-old Audrey Hale opened fire. (Metropolitan Nashville Police Department)

Investigators served a search warrant at Hale's home about three miles away from the church and school.

Hale was an artist who attended the Nossi College of Art and Design.

The killer was also recently seeing a doctor due to an emotional disorder and had legally purchased the seven guns from five stores leading up to the attack, police said.

Hale slept with journals on other school shootings under her bed in her parents' house. Police seized the journals and a trove of documents and electronic devices, court filings reveal. Hale also left behind a suicide note on a desk under one of several laptops police recovered near a list of passwords in the bedroom.

The house of alleged Covenant School shooter, Audrey Hale, is boarded up.

The house of Covenant School shooter Audrey Hale is boarded up in Nashville, Tennessee, on March 28, 2023.  (KR/Mega for Fox News Digital)

Hale's parents were unaware that the school shooter owned any guns after purportedly selling the single one they knew about, Chief John Drake said in March.

"They were under the impression that when she sold the weapon, she did not own any more," he said. "As it turned out, she was hiding several weapons inside the house."

Armed with three guns, Hale arrived at the school around 10:15 a.m. on March 27, blasted out a side door and went on a rampage inside.

Nashville shooter's weapons

Police recovered this weapon and two others at the scene of a mass shooting at The Covenant School in Nashville, Tennessee, on March 27, 2023. (Nashville Police Department )

When Hale burst in, the first victim, Hill, sustained fatal gunshot wounds in the process. According to city officials, Koonce heard the first shots while on a Zoom call, hung up and confronted Hale. Police found her dead in the hallway outside her office.

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Drake said investigators had not immediately determined a motive but believed that Hale, a former student, had targeted the school and its affiliated church.

By 10:30 a.m., responding officers fatally shot the killer on the second floor.