In a Texas courtroom, a troubling video was presented, showing a former FedEx driver, who has admitted to killing 7-year-old Athena Strand, seemingly switching between different personas. His defense team argues that his life should be spared due to his ongoing mental health challenges.

Tanner Horner, aged 34, entered a guilty plea for the kidnapping and murder of young Athena right before his trial was scheduled to commence in Fort Worth this week. Now, a jury faces the decision of whether to sentence him to life imprisonment or the death penalty.

The jury has spent several days reviewing body camera footage and police interrogation videos capturing Horner’s interactions with law enforcement following his arrest. This evidence is crucial as they deliberate over his potential death sentence.

Lindsay Thompson, Horner’s defense attorney, has attempted to evoke sympathy from the jury by highlighting his diagnoses, which include autism, brain damage, mental illness, and significant lead exposure.

According to allegations, former FedEx driver Tanner Horner hit Athena Strand with his vehicle on November 30, strangled her, and concealed her body approximately 10 miles from her father’s residence.

On Thursday, the courtroom viewed unsettling body camera footage where Horner instructed officers to speak to an alter ego he called “Zero.”

“Hey Zero, when you took her, was she wearing a jacket or anything?” the officer said in the clip, referring to Athena. 

“No jacket, no shoes,” Horner, speaking as Zero, replied. 

The apparent personality switch seemingly came out of nowhere during Horner’s interaction with law enforcement, raising red flags for Dr. Carole Lieberman, a forensic psychiatrist and expert trial witness. 

Tanner Horner listens during the first day of his capital murder trial at the Tim Curry Criminal Justice Center in Fort Worth, Texas, on April 7, 2026. He is charged with kidnapping and killing 7-year-old Athena Strand in 2022. (Juan Figueroa/The Dallas Morning News)

“What stands out the most, from a criminal profiling perspective, is the multiple sides that Horner has presented of himself in different scenarios,” Lieberman told Fox News Digital. 

“He has seemed perfectly sane at times, while he also claims to have a separate identity or alter ego, which could mean that he was being manipulative – like a malingerer or psychopath at other times.” 

WATCH: Athena Strand’s killer says he ‘just kind of tossed her’ in woods

As the body camera video continued to play, jurors heard authorities directly address Zero upon learning that the alter ego appeared to be more “helpful.” 

“So did you hit her before you dropped the package? I’m sorry, did Tanner hit her before the package was dropped off, or after?” the officer asked. 

“Do you want to talk to him?” Horner replied, referring to himself. 

A newly released photo shows 7-year-old Athena Strand shortly before prosecutors say she was abducted and killed by a FedEx driver delivering her Christmas present. (POOL via KDFW-TV)

“No, I want to talk to Zero. I want to talk to you. Because you’re being more honest, you’re more helpful,” the officer said. 

In light of the video, Lieberman suggests Horner’s alter ego could be a way for him to avoid accountability for his actions. 

“Sometimes criminals like to call the ‘bad’ part of themselves a separate identity, so that they don’t have to own it,” Lieberman said. 

“It can be a coping mechanism – when the person splits off the part of his personality he doesn’t want to acknowledge – or it could be psychopathic manipulation or malingering.”

Jurors were shown evidence pictures of the interior of Tanner Horner’s FedEx vehicle as well as bungee cords on Friday, April 10, 2026. Horner kidnapped and strangled 7-year-old Athena Strand in the FedEx vehicle on Nov. 22, 2022. (KDFW-TV)

However, Lieberman noted that most criminals claiming to have an alternate personality typically drop the act once in custody, unlike Horner. 

“In my experience, violent offenders do sometimes try to claim a separate identity or alter ego,” Lieberman told Fox News Digital. “But they usually give it up under intense psychiatric evaluation, or when they are ‘busted.’”

Interrogation video played for the court also showed Horner pleading with investigators to allow him out of jail for a month so he could spend one last Christmas with his family, while also appearing to show remorse for the strangulation of Athena. 

“Did you know what you did was wrong?” Texas Ranger Job Espinoza asked him, according to FOX 4.

“Of course,” Horner said. “I haven’t been on that medicine for five days, and it’s starting to wear off. I’ve actually been crying. Do you know what it’s like, not being able to cry for months and months and months?”

“I’m a father,” he continued as he grew emotional. “All I want is to spend one last Christmas with my son, and I’ll tell you everything.”

Lieberman points to Horner being a father and holding a job as a FedEx driver as a potential snag for his defense surrounding his history of mental illness. 

“Horner’s job history would hold clues too,” Lieberman said. “If he has just held low functioning jobs, or if he’s been fired from jobs a lot, this could speak to his autism or brain damage.”

WATCH: Tanner Horner pleads guilty to killing Athena Strand

“But people with autism or brain damage aren’t as able to make up stories about having an alter ego.” 

Horner initially claimed he accidentally struck Athena with his delivery truck while delivering a package to her father’s home, but later admitted to abducting and strangling her in November 2022 in Paradise, Texas.

He previously said he “kind of tossed” the young girl into the woods after killing her, according to an interrogation video shown to jurors.

Prosecutors have revealed evidence showing Horner covered a camera inside his FedEx truck before launching an extensive attack against Athena as she fought back. He later disposed of her body in a wooded area near Boyd, Texas.

Authorities said he then returned to work, continuing to deliver packages in nearby neighborhoods as authorities launched a desperate search for the girl. Her body was located three days later. 

Lieberman suggested jurors will likely have a strong emotional reaction to the case, given that it involves the murder of a young child, and may not put much weight into Horner’s mental health defense.

“Cases involving children cause people to have strong emotional reactions because they quickly identify with the child – both in terms of their own children and in terms of themselves when they were a child,” Lieberman said. “So they usually want the strongest punishment for the perpetrator and have little patience or compassion for a mental health defense.” 

“What makes this case even less sympathetic is that Horner was delivering Barbie dolls for her Christmas present,” Lieberman added. “A chilling juxtaposition of sweetness with evil.”