Cynthia Randolph faces life in prison for allegedly locking her children in the car on a 96-degree day

A grand jury has indicted a young Texas mother in the deaths of her two toddlers after she allegedly left them in a hot car for several hours in May.

PEOPLE has confirmed that 24-year-old Cynthia Marie Randolph has been indicted on two charges of injury to a child causing serious bodily injury. Earlier this month, the medical examiner’s office determined that 2-year-old Juliet Ramirez and her 16-month-old brother, Cavanaugh Ramirez, died of heatstroke. Their deaths were ruled homicides.

According to police, Randolph initially claimed the children “took off” and locked themselves inside her small vehicle, forcing her to break a window in an attempt to save them, according to the arrest affidavit obtained by PEOPLE.

But Randolph allegedly changed her story several times before revealing that she had found her children playing in the vehicle and left them inside after her daughter refused to leave, the affidavit states.

Mom Arrest Child Deaths
Cynthia Randolph
| Credit: Parker County, Texas sheriff's office/AP

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Randolph “shut the car door to teach her daughter a ‘lesson,’ thinking, ‘she could get herself and her brother out of the car when ready,’ ” police alleged in the affidavit.

She allegedly “then told investigators she went into her home, smoked marijuana and went to sleep for two to three hours,” authorities wrote.

Randolph also allegedly admitted to breaking the car window to “make it look like an accident,” authorities state.

Temperatures that day reached 96 degrees — the hottest at that point in the year, according to the Fort Worth Star-Telegram.

The prosecutor says that the charges are first-degree felonies. If Randolph is convicted, she faces up to life in prison.

“The culpable mental state required for first-degree-felony injury to a child is that the defendant knowingly engaged in conduct that was reasonably certain to cause serious bodily injury or death,” Parker County Assistant District Attorney Jeff Swain wrote in an email to the Star-Telegram. “By comparison, to prove a murder or capital murder, it must be proven that the defendant specifically intended to cause the death of the child.”

Randolph remains in jail on $200,000 bond and has not yet entered a plea.

She is represented by the public defender’s office. The office did not return PEOPLE’s call for comment.