Police say shifting explanations for the injury to her 2-month old son led Maria Benavides-Ruiz to be accused of causing serious bodily injury to a child

A Texas mom is facing a criminal charge after her 2-month-old son turned up at the hospital earlier this year with a skull fracture that she allegedly blamed on a ghost, PEOPLE confirms.

The husband of 21-year-old Maria Benavides-Ruiz, of Carrollton, at one point backed up her story, telling authorities he heard a “swoosh” in the middle of the night before being awakened by his wife, who pointed to the infant on the floor with a red mark on the side of his face, according to an arrest warrant obtained by PEOPLE.

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The husband said he tried to photograph the ghost on his cell phone — but when police took a look, they instead found text messages from his wife urging him to keep their stories straight, the warrant states.

“Hope they don’t find out it wasn’t an accident,” read one text, according to police.

Another text — sent about a month before the child’s skull injury was diagnosed on Feb. 23 by doctors at Children’s Health Medical Center — suggested Benavides-Ruiz struck her son when he failed to attach himself to her for breastfeeding, according to the warrant.

Carrollton police arrested Benavides-Ruiz on July 3 on a second-degree felony charge of injury to a child causing serious bodily injury. She was placed in the Dallas County Jail and released the same day after posting bond.

It could not be determined Tuesday if she has entered a plea or retained an attorney who could speak on her behalf. She could not immediately be reached directly.

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The “ghost theory,” which Benavides-Ruiz repeated during an April 6 polygraph, eventually gave way to her admission that she awoke in a panic after her son vomited on her in bed and she threw him, the warrant alleges.

The boy hit his head on a wooden dresser and later was taken to the hospital where doctors diagnosed a slightly depressed skull fracture, bleeding under the skull and a contusion to his brain — injuries that the medical staff determined could not have been caused by everyday accidents, according to the warrant.

As investigators dug deeper, the explanations given for the injuries by Benavides-Ruiz and her husband kept changing, according to the warrant.

Initially they blamed an accident that occurred when her husband tried to open a bag of diapers while holding the child and dropped him. The husband later said he concocted that story and then shifted to the claim about a ghost, repeating an account Benavides-Ruiz had earlier given to a family caregiver.

The warrant shows that during the April 6 polygraph, where she eventually allegedly confessed to the vomiting incident, Benavides-Ruiz said her husband had no idea what actually happened to the child. He does not face any charges.