Ex-DCF Worker Who 'Severely Abused' Adopted Teen, Locked Her In Garage Charged with Murder: Sheriff

According to the Highlands County Sheriff's Office, on Friday, Diane Natasha Mack, 34, called authorities and reported that she found her 13-year-old adoptive daughter "unresponsive" in their Sebring home.

When deputies responded to the scene around midnight on Friday morning, they reportedly discovered what they described as a "horrific crime."

The sheriff's office said they found the 13-year-old "lying unresponsive on the floor next to the front door." She was pronounced dead at the scene.

"The girl, who was nude except for a diaper, had clearly been severely abused. She was extremely emaciated and obviously malnourished," Highlands County Sheriff Paul Blackman said. "Her body was covered in wounds in all stages of healing, including open lacerations that were clearly recently suffered."

During the investigation, authorities reportedly discovered that the teen -- who was homeschooled -- had been "restrained in the garage," per the sheriff's office.

"Detectives don't yet know how long she had been held there, but it appears she was secured to the garage door and monitored from inside the home by a security camera that had been mounted in the garage," the release said.

Blackman also alleged that Mack attempted to cover up the evidence in the garage.

"While her child lay dead on the floor, the suspect had clearly used pool chlorine in an effort to destroy evidence in the garage before calling 911," he said.

According to the sheriff's office, Mack -- who is a former Florida Department of Children and Families employee and also worked as a guardian ad litem -- initially told authorities that she found her teen daughter on Thursday morning, but she later claimed it was "closer to 3 p.m."

While the exact time is unclear, authorities reportedly discovered that Mack "took the time" to drive four other children to Titusville, and returned home to Sebring before she called 911.

"This is one of the most disturbing crime scenes I have encountered in more than 30 years of law enforcement," Blackman said. "There are no words I can say that can truly convey the nightmare that this child's life must have been."

"Parents have a duty to love our children and make sure no harm comes their way. To see a child treated this way is not only heartbreaking, it is infuriating," he added. "What makes it even more appalling is that the suspect is a former employee of not only the Department of Children and Families, but also worked as a guardian ad litem. That someone whose job it was to look after the welfare of children could treat their own child in this manner is simply beyond belief."

Following her arrest, Mack was charged with first-degree murder while engaged in aggravated child abuse. In addition, she's charged with aggravated child abuse, kidnapping, and destroying evidence. Mack is being held without bail in the Highlands County Jail, per the sheriff's office.

If you are experiencing or witness child abuse, call the Childhelp National Child Abuse Hotline at 1-800-4-A-Child or 1-800-422-4453, or go to www.childhelp.org. If you believe a child is in immediate danger, call 911.