The security footage is something you don't forget easily. It shows a 14-year-old girl, Carly Gregg, walking into her kitchen with a dog trailing behind her. She looks like any other kid, maybe a little slumped in the shoulders, until she pulls a .357 Magnum from behind her back. Seconds later, off-camera, three shots ring out. That was the moment Ashley Smylie, a beloved math teacher at Northwest Rankin High School, lost her life at the hands of her own daughter.
People have been asking why did carly gregg kill her mom since the news first broke in Brandon, Mississippi, back in March 2024. Was it a snap decision? Was she "insane," as her defense team claimed? Or was there something much more calculated happening behind those glasses? Honestly, the trial peeled back layers of a "secret life" that nobody—not even her stepfather who lived in the same house—fully saw coming.
The Breaking Point: Vapes, Weed, and a Mother’s Discovery
To understand the "why," you have to look at the hours leading up to the trigger pull. On March 19, 2024, Ashley Smylie was told by one of Carly’s friends that the teen was using marijuana and had a "burner phone." For a mother who was also a teacher at her daughter's school, this wasn't just a parenting hurdle; it was a crisis of reputation and safety.
When they got home that afternoon, Ashley went straight to Carly’s room to search for the contraband.
Psychiatrists who testified during the trial, including Dr. Andrew Clark, suggested that Carly was "terrified" of losing her mother's approval. For a "genius" student who had skipped the fourth grade and scored a 30 on the ACT at age 13, the looming confrontation felt like the end of her world. The prosecution argued that instead of facing the music, Carly decided to eliminate the person holding the baton.
A "Secret Life" Exposed
Prosecutors didn't hold back. They painted a picture of a girl leading a double life. While the world saw a straight-A student, Carly was allegedly:
📖 Related: Trump New Gun Laws: What Most People Get Wrong
- Using various "THC products" and marijuana.
- Communicating with friends through devices her parents didn't know about.
- Dealing with a history of self-harm (cutting) that she hid from most people.
The defense tried to frame this as the byproduct of a crumbling mental state. They talked about her biological father's history of drug abuse—claiming he used to blow smoke in her face when she was a toddler—and how that trauma may have wired her brain differently. But for the jury, the "secret life" looked less like a cry for help and more like a motive to keep the secrets buried at any cost.
The Mental Health Defense: Was Carly Gregg Insane?
This is where the case gets really messy. During the trial, the question of why did carly gregg kill her mom turned into a battle of the experts. Her defense team, led by Bridget Todd, went all-in on an insanity plea. They argued that Carly was suffering from undiagnosed mental illness, specifically an "unspecified schizophrenic disorder" and depression.
Dr. Andrew Clark testified that Carly claimed her memory "went blank" the moment she let the dogs out. She told him she heard voices—a male voice that had been there since she was five or six years old. On the day of the shooting, those voices were reportedly getting louder.
But the prosecution had their own experts. Dr. Jason Pickett, a forensic psychiatrist, basically told the jury that Carly’s behavior was way too organized for someone in a "dissociative state."
- She hid the gun behind her back while walking through the kitchen to avoid being seen by her mom too early.
- She used her dead mother’s phone to text her stepfather, Heath Smylie, "Are you almost home, honey?" to lure him into an ambush.
- She asked a friend who came over, "Have you ever seen a dead body?" before showing her Ashley’s remains.
"If you try to cover up a crime, doesn't that indicate you know what you did?" the prosecution asked. That's a hard point to argue against. The jury took only two hours to decide she wasn't insane; she was just deliberate.
👉 See also: Why Every Tornado Warning MN Now Live Alert Demands Your Immediate Attention
The Medication Factor
There’s also the issue of her meds. Just a week before the shooting, Carly had switched medications. Her defense claimed this "cocktail" of drugs caused a psychotic break. However, Dr. Pickett pointed out that the dosages were extremely low—roughly half of a normal starting dose. He didn't buy that such a small amount of medication could push a person into a state where they couldn't distinguish right from wrong.
The Aftermath and the "Demon" Testimony
One of the weirdest parts of the trial was the testimony of Heath Smylie, Carly’s stepfather. He’s the one she tried to kill next. When he walked through the door, Carly fired at him, grazing his shoulder.
Even after being shot at, Heath testified that the girl he saw wasn't "his" Carly. He said she looked like she had "seen a demon" and was "screaming out of her mind." It’s a rare thing to see a victim of an attempted murder testify in a way that almost helps the shooter, but Heath seemed to believe she was truly having a mental break.
Despite his testimony, the surveillance audio of her screams and the cold, calculated texts she sent told a different story to the jury. After she shot her mom, she sat on a kitchen stool and calmly texted her friends. She didn't look like someone who had just seen a demon; she looked like someone waiting for the next phase of a plan.
Why the Verdict Was Life Without Parole
In Mississippi, the legal standard for insanity is the M'Naghten rule. It basically asks: Did the person know what they were doing, and did they know it was wrong?
✨ Don't miss: Brian Walshe Trial Date: What Really Happened with the Verdict
Because Carly hid the weapon, lured her stepfather home under false pretenses, and fled the scene when the plan failed, the state argued she knew exactly how wrong it was. You don't hide evidence of something you think is okay.
The jury agreed. In September 2024, Carly Gregg was sentenced to:
- Life in prison for the first-degree murder of Ashley Smylie.
- Life in prison for the attempted murder of Heath Smylie.
- 10 years for tampering with evidence.
The sentences run concurrently, but because there is no possibility of parole, the 15-year-old is essentially looking at the rest of her life behind bars.
Actionable Takeaways: What We Can Learn
While the Carly Gregg case is an extreme outlier, it highlights some pretty heavy realities about teen mental health and the "secret lives" kids lead today.
- Watch for "Performance" Behavior: Carly was a "perfect" student. Sometimes, the kids who seem the most "together" are the ones under the most internal pressure to maintain an image.
- Early Intervention Matters: If a child mentions "voices" or exhibits self-harm, it’s a medical emergency, not a phase.
- The Power of Digital Secrecy: Burner phones and hidden social media accounts are often the first sign that a teen is drifting away from parental influence into something potentially dangerous.
- Medication Monitoring: Any change in psychiatric medication for a minor should be monitored with extreme caution, involving daily check-ins on mood and behavior.
The tragedy in Brandon wasn't just about one bad day or one discovery of a vape pen. It was a perfect storm of undiagnosed (or under-treated) mental health struggles, access to a firearm, and the crushing weight of a "genius" child's fear of failure.
If you are following the legal updates, Carly's team has already filed for an appeal to the Mississippi Supreme Court as of late 2024, citing "new evidence" regarding her biological father's testimony. Whether that changes her fate remains to be seen, but for now, the answer to why did carly gregg kill her mom remains a chilling mixture of a teen’s "crisis of approval" and a hidden mental health spiral that ended in the worst way possible.