Tanner Horner is currently awaiting sentencing after pleading guilty to murder

Former FedEx driver Tanner Horner pleads guilty to killing 7-year-old girl.
Tanner Horner.WFAA/YouTube

The letter addressed to the victim’s family reportedly stated, “I can’t tell you how many countless nights I’ve stayed awake, unable to sleep,” according to CBS.

“I pray for all of you. So many people were affected by my breakdown,” the letter reportedly continued. “Not just your family but my own as well. You’ll never get to see your baby girl grow up and I’m sorry. Now my son is going to grow up without his father and protector.”

Horner further claimed that prior to Athena’s murder, he had experienced a work-related mental health crisis.

“I’m sorry I allowed my mental state to be unstable,” he wrote, according to the outlet. “I’m sorry I took your little angel away from you. She didn’t deserve it. Y’all didn’t deserve it.”

The letters were found in Horner’s cell following a suicide attempt months after Athena’s murder, NBC DFW reported.

Athena died from blunt force trauma, smothering and strangulation, a medical examiner ruled.

Her naked body was found in a river nearly 9 miles away from her home.

Jurors are weighing whether Horner will be sentenced to death or life in prison without parole.