Nashville mass shooter Audrey Hale hid her cache of weapons from her parents, who didn’t want her to own guns due to an emotional disorder she was being treated for, police revealed Tuesday.

Hale, 28, who was transgender, had legally purchased seven guns from various local stores — including the three she used to kill six victims at the Covenant School on Monday, Metropolitan Nashville Police Chief John Drake said.

According to Drake, Hale’s parents told investigators they only knew about one of the guns but they believed she had sold it sometime before the massacre that left three 9-year-olds and three adults dead.

“She was under care, doctor’s care, for an emotional disorder,” the police chief said without elaborating, adding that cops “knew nothing about the treatment she was receiving.”

Drake previously said police are looking into whether Hale’s gender identity played a role in the slaughter. It’s unclear whether Hale identified as man or a woman, but cops have referred to her using female pronouns.

Hale used male pronouns and the name Aiden on some social media accounts.

“Her parents felt she should not own weapons … they were under the impression that when she sold the one weapon that she did not own any more,” Drake added.

“As it turned out, she had been hiding several weapons within the house.”

Cops uncovered the weapons — as well as a manifesto — when they raided Hale’s family home in the aftermath of the deadly tragedy.

Drake said the shooter’s mom told detectives she’d asked Hale what was in a red bag she was carrying when she left the house — but her daughter was dismissive.

He added that the mom didn’t think to look in the bag because she didn’t know Hale still owned firearms.

The police chief said there’s no law in Tennessee that would have allowed authorities to take away Hale’s guns based on her being under the care of a doctor, but he insisted that cops would have made every effort to do so if they had known she was suicidal.

“As it stands, we had absolutely no idea … who this person was, that she even existed,” he said.  

Asked whether Hale was autistic, Drake said he couldn’t confirm that.

Follow The Post’s coverage ofthe school shooting in Nashville

Neighbors told The Post on Tuesday that cops used “flash grenades” to storm Hale’s home.

“They broke the door down to get in,” said one neighbor, who didn’t want to be named.

Another neighbor described the sound of the flash grenades as being like “f—ing cannons.”

“It was loud as hell,” he added.

Cops still haven’t determined a motive for the massacre, but it appears the victims were gunned down at “random,” Drake said.

The fatally wounded victims were found in various locations throughout the building, he added.

Hale was eventually killed in a shootout with cops in an atrium on the second floor of the school.  

The victims have since been identified as Evelyn Dieckhaus, Hallie Scruggs and William Kinney, all 9, as well as custodian Mike Hill, 61, substitute teacher Cynthia Peak, 61, and headmaster Katherine Koonce, 60.