Rankin County deputies arrested a 14-year-old for allegedly killing her mother and injuring her step-father during a shooting.

The defense attorney for Carly Gregg said the 15-year-old deserves a new trial because she was previously treated for hearing voices using horse therapy.

He told the deputies had arrived home and found his wife, 40-year-old Ashley Smylie, dead from a gunshot wound and his stepdaughter still armed with a handgun.

Carly Gregg, 15, is currently on trial for allegedly killing her high school teacher mom, Ashley Smylie, and then shooting her stepdad, Heath Smylie, in their Brandon, Miss., home back in March ...

It’s the chilling question then 14-year-old Carly Gregg asked her friend after she shot and killed her mother, high school teacher Ashley Smylie, inside their Mississippi home earlier this year ...

He told deputies he came home to find his wife shot to death, authorities told the station. Officials identified the slain woman as 40-year-old Ashley Smylie.

Carly Madison Gregg is being charged with one count of murder in the death of 40-year-old Ashley Smylie, an algebra teacher at Northwest Rankin High School. (Credit: Rankin County Sherrif's Office ...

Mississippi girl Carly Gregg, 15, seen texting stepdad seconds after allegedly fatally shooting mum Ashley Smylie, who discovered her ‘secret life’ Chilling video has shown a teenager calmly ...

A 14-year-old Mississippi girl accused of killing her mother is being charged as an adult, according to authorities.