Amber Guyger, left, is serving a 10-year sentence for the murder of Botham Jean.
Dallas CNN  — 

An attorney for Amber Guyger, the White former Dallas police officer convicted of killing of Black neighbor Botham Jean in his apartment, asked a Texas appeals court Tuesday to acquit her of murder or find her guilty of a lesser charge.

Guyger testified at her 2019 trial that after working long hours on September 6, 2018, she returned to her Dallas apartment complex. In uniform but off duty, she approached what she thought was her apartment. She noticed the door was partially open, saw a man inside who she believed to be an intruder and fired her service weapon, killing him.

She was actually at the apartment directly above hers– where Jean, a 26-year-old PricewaterhouseCoopers accountant, lived. Prosecutors said Jean had been on the couch in his shorts, watching TV and eating vanilla ice cream when Guyger walked in and fatally shot him.

In October 2019, a jury found Guyger guilty of murdering Jean and sentenced her to 10 years in prison.

Guyger’s defense claims there was insufficient evidence to convict her of murder. The defense has asked the Fifth District Court of Appeals in Dallas to either acquit Guyger of that charge or make a finding of criminally negligent homicide – which carries a punishment of six months to two years – and hold a new hearing on the punishment.

Jean’s mother, Allison, told CNN she was confident the appeals court would uphold the murder conviction.

“Amber Guyger needs to sit where she is in prison and accept responsibility for what she did to my son, my family, my country, my world,” Allison Jean said in a phone interview Tuesday from her home in St. Lucia.

Guyger’s lawyer, Michael Mowla, argued before the three-judge appeals court that Guyger’s mistaken belief she was in her own apartment negates “evil intent” to kill. A conviction of criminally negligent homicide, he argued, would be more appropriate.

“Mr. Mowla, you’re overlooking the fact that Miss Guyger testified that she intentionally shot Mr Jean,” Chief Justice Robert D. Burns III told the attorney. Burns at one point suggested that Guyger’s conviction was in fact supported by the legal precedent raised by the defense.

“I’m not overlooking the fact, your honor. I agree,” Mowla responded during the Zoom hearing. “She did intentionally shoot Mr. Jean because that was her intent. That was the truth. Those were the facts of the case. If she had walked into her apartment, and there was an intruder inside her apartment …. she would have been entitled to use deadly force in self-defense.”

In the appeal, Guyger’s lawyers said that “her mistaken belief negated the culpability for murder because although she intentionally and knowingly caused Jean’s death, she had the right to act in deadly force in self-defense since her belief that deadly force was immediately necessary was reasonable under the circumstances.”

“Intentionally or knowingly killing another human is an evil act,” Mowla argued Tuesday. “And that’s what she was convicted of. The problem is that when she entered what she thought was her own apartment, she did not have evil intent.”

The state, represented by Dallas County Assistant District Attorney Douglas Gladden, argued that mistaken belief and mistake of fact is not a justifiable defense.

“This is a murder case, not a criminal trespass case. When Amber Guyger shot Botham Jean, she didn’t take someone else’s property. She took the life of a human being,” Gladden told the appeals courts.

“She didn’t make a mistake about that. She knew Botham was a living human being. She pointed a gun at him. She intended to kill him. That’s murder. It’s not negligent. It’s not mistake of fact. It’s not justified.”

A week of testimony at trial revealed Guyger had had a sexual relationship with her partner on the force and texted him before and after the shooting, including two texts sent while she was reporting the shooting to a 911 dispatcher.

Her lawyers have said she was tired after working long hours and wasn’t paying attention to the many cues that prosecutors said should have tipped Guyger off that she was on the wrong floor, in the wrong apartment. Jean’s apartment was on the floor above.

Guyger testified that she hated herself and asked for forgiveness every day.

“I hate that I have to live with this every single day of my life,” she said, in tears.

“I ask God for forgiveness, and I hate myself every single day. … I wish he was the one with the gun who had killed me. I never wanted to take an innocent person’s life,” she said.

On the final day of the murder trial Jean’s younger brother, Brandt, told Guyger during his victim impact statement that he forgave her, and gave her a long hug before she was taken to prison.

Guyger is serving her 10-year sentence at the Mountain View prison in Gatesville. She is eligible for parole on September 29, 2024.

Guyger did not appear at the virtual hearing. The court said it would issue its opinion at a later date.

Allison Jean said Guyger’s 10-year sentence is still not enough. Had roles been reversed, she said, her son would be facing a much longer prison term.

“He was destined to lead this world. For his life to be taken away from us in such a careless manner, she needs to be given more time for what she did,” Allison Jean said.

The appeal arguments took her back to the day her son was killed.

“Our life has just been turned upside down as a result of Amber Guyger’s action, and she needs to leave us alone right now,” Allison Jean said. “She’s done enough harm.”

Ashley Killough reported from Dallas and Ray Sanchez reported and wrote from New York.