Defense Focuses on Autism, Trauma, and Family History

Day 15 of the Tanner Horner trial continued the defense’s mitigation case, with jurors hearing from mental health and autism experts before Horner’s grandmother took the stand. Horner has already pleaded guilty to capital murder and aggravated kidnapping in the 2022 abduction and killing of 7-year-old Athena Strand, leaving jurors to decide whether he should be sentenced to death or life in prison without parole.

Dr. Eric Imhof Testifies About Horner’s Mental Health

The first witness of the day was Dr. Eric Imhof, a forensic psychologist who evaluated Horner in jail over three days. Imhof confirmed Horner’s autism diagnosis and also diagnosed him with PTSD, Bipolar I disorder, depression, and generalized anxiety disorder.

Imhof told jurors he reviewed Horner’s abduction and interrogation videos and saw some signs of anxiety. He also addressed Horner’s claim about an alter ego named “Zero,” concluding that it was not a real multiple personality.

On cross-examination, prosecutors focused on the limits of Imhof’s evaluation. They noted that some testing relied on Horner’s own self-reporting, and Imhof testified that Horner did not tell him he used cocaine on the day of the offense.

Autism Expert Discusses Horner’s Functioning

The defense next called Dr. Kim Spence, an expert who works with people with autism and trains professionals on how to understand and interact with autistic people. Spence testified that people with autism can struggle with generalizing skills, meaning someone may learn a skill in one setting but have difficulty applying it in a different environment later.

Spence also said she disagreed with the decision to discontinue Horner’s disability services when he turned 18. According to another trial summary, she told jurors Horner met the criteria for autism spectrum disorder and described a troubled upbringing that included incarcerated parents and his grandmother stepping in to help care for him.

When asked whether Horner’s conditions directly caused the crime, Spence said they did not, but said they could have played a role.

Horner’s Grandmother Describes His Childhood

After lunch, Horner’s maternal grandmother, Jackie, testified about her family history and her role in raising him. She described growing up in a family affected by alcoholism and sexual abuse, and said two of her siblings died by suicide. She also told jurors she became pregnant at 15 and dropped out of school in the 10th grade.

Jackie testified that Horner’s mother struggled with abusive relationships, teenage pregnancy, and drug use. She said she took over Horner’s care at his mother’s request because his mother was battling addiction.

She told jurors that both she and Horner’s mother recognized he was different from other children. After he was diagnosed with ADHD and Asperger’s syndrome, Jackie said she felt relieved to understand what was going on.

Jackie also described Horner being bullied. In one incident, she said another child called him names at a wrestling match, and Horner responded by telling her, “Oh, it’s okay, Mimi. I’m used to it.” She said she was proud when Horner graduated high school because he was the first person in their family to do so.

A Family Member Apologizes in Court

Jackie also testified about calling Horner after Athena was reported missing, not knowing he was responsible. She said she asked him to look out for the missing girl, and described his response as generic.

She apologized to Athena Strand’s family during her testimony. On cross-examination, prosecutors pressed her on whether Horner was responsible for what happened, rather than his autism diagnosis. Jackie said she believed his problems had something to do with it, but acknowledged that Horner knew right from wrong, knew not to kill, and knew not to sexually assault a child.

When defense attorneys asked if she was angry with her grandson, Jackie said she was, but added that she still loved him.

Where Day 15 Leaves the Case

Day 15 continued the defense effort to show jurors Horner’s life history, diagnoses, and family background before they decide his sentence. The testimony focused on autism, mental health, trauma, and the role his grandmother played in raising him.

Prosecutors used cross-examination to bring the focus back to responsibility, self-reporting, and whether Horner understood right from wrong. The day ended with jurors dismissed for the week, and testimony expected to resume the following Monday.