Harrowing moment teen girl 'shoots mom dead then calmly texts stepdad'

A teenage girl accused of shooting her mom dead and attempting to kill her stepdad was filmed playing on her mobile phone and texting a friend just moments after shots were fired.

Harrowing footage of Carly Gregg casually wandering around her kitchen has been played in court during her murder trial in Mississippi.

The now 15-year-old was just 14 when she allegedly shot her mom inside their home on March 19. She turned down a 40-year plea deal and her legal team is instead pursuing an insanity defense. 

In the video, Gregg walked into the kitchen wearing a Nirvana t-shirt and paced up and down the corridor, disappearing off camera briefly before returning, holding something behind her back, and peering into the kitchen.

She walked off camera again in the opposite direction moments before three gunshots rang out. 

After the first shot, a woman was heard screaming, and then the room fell silent.

Moments later, Gregg was again seen camera, casually taking a seat on a stool near the kitchen bench and texting on her phone as her two dogs watched on.

Gregg's mother, 40-year-old math teacher Ashley Smylie was fatally shot in the face. 

Prosecutors allege Gregg then used her mother's phone to text her stepfather Heath in an effort to lure him home, Law and Crime reported.

A text message sent from Smylie's phone to Heath read: 'When will you be home honey?'

When Heath returned home, police allege Gregg shot at him, hitting him once in the shoulder.

The court heard Heath wrestled the gun from Gregg before she could shoot him again, prompting her to flee the scene.

Police allege that while on the phone, Gregg text one of her friends, known by the pseudonym B.W, asking them to come over to the house due to an 'emergency.'

When the friend arrived, Gregg allegedly asked her 'if she had ever seen a dead body before' and led the witness to her mother's body.

Heath testified in court about seeing his wife's body when he got home.

'I knew that she had been shot, there was blood around, I'm not sure exactly where, on the right side of her face.'

He said Gregg had once been a 'sweet little girl' but looked like 'she had seen a demon' on the day in question.

'When I opened the door to the kitchen, the gun went off in my face before the door was three or four inches wide open,' he claimed. 

'The gun flashed in my face. It went off two more times, but my hand was on the gun after the first shot, and I twisted it from Carly.'

The court heard on Wednesday from psychiatrist Dr Andrew Clark, who said he believes Gregg 'blacked out' for up to 90 minutes on the day of the alleged offence.

But he also accepted that someone in Gregg's position would have a motive to 'fake' a mental illness.

Dr Clark told the court Gregg reported to him that she'd had 'auditory hallucinations' for years prior to the alleged crime, but the voices in her head had never 'commanded' her to do anything.

Gregg had confided in Dr Clark that she had started smoking marijuana, several times per week and was concerned that her mother would find out, the court heard.

The court heard she had used marijuana up until at least the day prior to the alleged incident. She had also been prescribed Lexapro and Zoloft - both medications for mood disorders.

She is charged with murder, attempted murder and evidence tampering, and faces a life sentence if found guilty.