A New Mexico couple is facing murder charges after allegedly stabbing and nearly decapitating a 21-year-old woman with a sword, say authorities.

On Oct. 29 at 1:44 p.m., officers were called to a Santa Fe home on a report of a possible homicide, the Santa Fe Police Department said in a statement.

Upon arrival, officers found the body of a young woman, later identified as Grace Jennings, in a detached garage on the property, police said.

According to the criminal complaint obtained by PEOPLE, Jennings's body showed "several injuries consistent [with] being cut or stabbed with a sharp object." Her body also appeared to have injuries "consistent with attempts to decapitate."

Officers also found what appeared to be a bloody sword inside of the garage, according to the complaint.

On Sunday, police arrested Kiara McCulley, 19, and her boyfriend Isaac Apodaca, 25, and charged them with one open count of first-degree murder in connection with Jennings' death, say police.

They are also charged with conspiracy to commit first-degree murder, online court records show.

McCulley is also charged with tampering with evidence.

They have not yet entered pleas.

According to the complaint, Apodaca's mother, Linda Montoya, told police that her son said he "found his girlfriend killing another female in the garage." Apodaca then called 911 and alleged his girlfriend killed someone with a sword, the complaint says.

When officers arrived, they saw a woman later identified as McCulley run inside the back door of the house and shut the door, the complaint says.

After the couple was taken in for questioning, authorities determined the suspects and the victim had slept in the same bed on the night of Jennings' death.

The complaint states that both Apodaca and McCulley had prior romantic relationships with Jennings. But McCulley said she was angry with Jennings, claiming Jennings had watched her allegedly being raped by "16 or 17 males" and "collected money" during the incident, the complaint states.

In an interview with The Santa Fe New Mexican, Santa Fe Police Capt. Aaron Ortiz confirmed that a sexual assault was reported in 2020 "but not with the details that [McCulley] claimed during her interview."

Of the night of the killing, McCulley allegedly said she had mental health challenges, and she'd "had a period of time where she could not remember what had happened," according to the complaint. But according to the complaint, she allegedly said she was "partially hopeful" Jennings was dead.

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She allegedly told detectives she had "fantasized multiple times" about killing Jennings in particularly disturbing ways, according to the complaint.

Claims of a 'Secret Society'

Apodaca told police he had nothing to do with Jennings' slaying but that McCulley had allegedly been planning to kill her since 2020, according to the complaint.

But detectives found suspicious messages on his phone, allegedly indicating otherwise.

One of the messages he allegedly sent to McCulley said, "Remember, you'll move up the perks in the black market since this is your first," the complaint says.

He also wrote in another message, "I am wanting you to kill her, you have to end your suffering by ending her joy," according to the complaint.

When detectives asked him about this, Apodaca replied, "I do mean what it says in that text," and allegedly admitted he meant that he wanted McCulley to kill Jennings.

McCulley told detectives that Apodaca "is in charge of a secret organization called 'Ghost,'" which "gets rid of people who are in charge of sex trafficking or hurting kids," the complaint says.

She said Apodaca "kept telling her to kill Ms. Jennings so that [McCulley] could get ranked up in her platoon," the complaint says.

She said at one point she had "a dagger in her hand and was trying to stab Ms. Jennings but didn't do it," according to the complaint.

When the detective asked McCulley if she killed Jennings, she replied, "I'm not sure," the complaint says.

Police say the investigation is ongoing.

It is unclear whether Apodaca or McCulley have retained attorneys who can speak on their behalf.

A GoFundMe has been set up to help defray the costs of the funeral for Jennings.

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