An Ohio mother has been charged with murder for allegedly stabbing her adult daughter in the back with a collectible “short sword” that her husband owned. This tragic incident unfolded during a heated argument, authorities report.

According to police, 49-year-old Terri Niner allegedly called 911 following the incident, describing past disputes with her daughter, Ayla Mangan, 32, on July 10 and other occasions over “some dumb stuff,” as noted by The Repository.

Documents, including Niner’s criminal complaint and the police report accessed by the publication, outline her conversation with the dispatcher. Additionally, her husband, Francis Niner, faces an obstruction charge for allegedly not providing full details to the authorities.

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“Please help us, please,” Terri Niner allegedly said.

“Did you cut her?” the dispatcher asks, per the Repository.

“No, I grabbed the knife from her, and she went to throw herself backwards because she’s autistic,” Terri allegedly replied. “And when she went to throw herself backwards, it got her. And I thought it only cut her a little bit.”

The Niners were arrested by Canton police on Thursday afternoon and given a July 16 court date after being charged. Francis Niner told cops that he collects swords and displays them in his home. The one Terri allegedly used was hanging in the living room.

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Francis, who goes by “Jay,” is accused of being “untruthful” to investigators and deliberately withholding information relevant to the homicide probe in an effort “to protect” his wife, the complaint alleges. He is Mangan’s stepfather.

“The allegations are very serious,” said Elise Hamilton, senior trial counsel in the Canton Law Department, at Terri Niner’s bond hearing. She reportedly confirmed to the judge that Mangan was autistic and had the functional level of a 13-year-old.

Bond for Niner was set at $500,000.