SEE IT: 14-Year-Old Accused Killer Seen Calmly Using Phone After Shooting Math Teacher Mother in Face, Chest

Security footage shown at a Mississippi girl’s murder trial Tuesday appeared to capture her hiding something behind her back moments before gunshots ran out, then calmly using her mother’s phone.

Carly Gregg is accused of killing her mother, Ashley Smylie, 40, during a March 19 shooting inside their Brandon home. She’s is also accused of shooting and wounding her stepfather, Heath Smylie, as CrimeOnline reported.

Gregg is currently on trial in Rankin County, facing charges that include murder and attempted murder.

The video, obtained by Law&Crime, recorded on March 19, showed Gregg, then 14, at the home when her mother, a math teacher in Rankin County, was fatally. After the shooting, Gregg was seen in the kitchen using a phone, with the family dogs nearby.

Mississippi state prosecutor Kathryn White Newman said Gregg then messaged her friend to come over for an “emergency.”

“Are you squeamish around dead bodies?” Gregg asked the friend, then led her to her mother’s body, who had died on a bedroom floor after being shot three times.

The Clarion Ledger reports that Rankin County investigator Zachary Cotton told the court that Gregg told her friend that there were three shots, “two for the head, one for the chest.”

Gregg then used her mother’s phone to lure Heath to the house, pretending to be her mother, the prosecution said. She then allegedly shot him as Heath fought back and grabbed the gun.

Police tracked the teen by helicopter and arrested her shortly after.

Meanwhile, prosecutor Corey Gerber testified that Gregg tested positive for marijuana upon arriving at the Rankin County Youth facility. Newman added that Gregg admitted to using marijuana on or around March 18, the day before the shootings.

“We believe that this information is certainly pertinent since (Gregg) has asserted her right to claim an insanity defense. … Once the defendant puts their sanity at issue, the door is thrown wide open for the admission of evidence of every act of the accused’s life relevant to the issue of insanity or sanity and is admissible in evidence,” Newman said.

Gregg is currently behind bars at the Rankin County Jail in Brandon. Due to the seriousness of the charges, she is being tried as an adult.

The trial continues. Check back for updates.

For the latest true crime and justice news, subscribe to the ‘Crime Stories with Nancy Grace’ podcast.

Join Nancy Grace for her new online video series designed to help you protect what you love most – your children.

[Featured image: Carly Gregg/Instagram; Ashley Smylie/Rankin County School District]