A late-night visit to a Las Cruces hospital quickly escalated into a homicide investigation after medical staff realized something was terribly wrong.

On Feb. 7, a woman arrived at Memorial Medical Center showing clear signs she had recently given birth — but there was no baby with her. Concerned, hospital staff contacted police.

The woman was later identified as Sonia Jimenez. As officers began piecing together what happened, they learned from her boyfriend that he believed she had suffered a miscarriage. He told authorities the couple had been at Burn Lake earlier that evening and that Jimenez had used a portable toilet at the site.

Officers searched the area, focusing on the port-a-potty near the lake, about six miles from the hospital. Inside the unit’s holding tank, they found the body of a newborn girl.

An autopsy later determined the infant had been born alive. Police said blue chemical residue from the portable toilet was found in the baby’s airway and stomach, indicating she had breathed and swallowed the liquid.

Jimenez was arrested Wednesday and charged with one felony count of intentional child abuse resulting in death. She is being held without bond at the Doña Ana County Detention Center.

Las Cruces Police Chief Jeremy Story called the case one of the most disturbing he has encountered and said investigators are working with prosecutors to pursue justice for the newborn.