Cheyanne Harris Case: Charges, Life Sentence, and Appeal

Cheyanne Renae Harris is an Iowa woman serving life in prison without the possibility of parole for the first-degree murder of her four-month-old son, Sterling Koehn. The Cheyanne Harris case arose after the infant was found dead on August 30, 2017, in a mechanical baby swing in the family’s apartment in Alta Vista, Iowa, severely malnourished and infested with maggots. A jury convicted Harris in February 2019, and the Iowa Court of Appeals affirmed her conviction in January 2021.

What Happened to Sterling Koehn

Sterling’s father, Zachary Paul Koehn, called 911 on August 30, 2017, and told dispatchers the baby had died of sudden infant death syndrome. Chickasaw County sheriff’s deputies arrived at the couple’s Alta Vista apartment and found the infant’s body in a dark, hot bedroom, in a mechanical swing. He weighed less than seven pounds, far below the fifth percentile for his age.¹²

Toni Friedrich, a nurse and EMT who was the first to respond, testified that Sterling’s clothing was “crusty,” that gnats flew up when she moved his blanket, and that his eyes were open in a “blank stare.”² A forensic entomologist later concluded the baby had not been removed from the swing or had a diaper change for nine to fourteen days. Flies had laid eggs in the soiled diaper, and maggots at various stages of development were found on the child’s skin and clothing.³

Cause of Death

The Iowa state medical examiner ruled Sterling’s death a homicide caused by “failure to provide critical care.” The autopsy identified malnutrition, dehydration, and an E. coli infection as the causes of death.¹ Prosecutors said feces in the unchanged diaper had eroded and ruptured the infant’s skin, letting E. coli bacteria enter his bloodstream. The criminal complaint described the circumstances as showing “an extreme indifference to human life.”³

Charges and the Trial

Harris, then 20, and Koehn, then 28, were each charged in Chickasaw County with first-degree murder and child endangerment resulting in death. They were tried separately. Both parents had acknowledged using methamphetamine, and Harris was being treated for post-traumatic stress disorder. Neither had a serious criminal history before Sterling’s death.⁴³

Harris’s trial was held in Plymouth County, Iowa, in early February 2019. Assistant Attorney General Coleman McAllister told jurors the case went “far beyond neglect” and pointed to the family’s resources, noting Koehn earned roughly $45,000 per year. Investigators testified that Harris had told a Division of Criminal Investigation agent, “I should have checked on him more.”¹

Public defender Nichole Watt acknowledged the death was a tragedy but denied it was a planned murder. She argued that Harris suffered from postpartum depression and had been self-medicating, telling the jury, “The monster, in this case, is mental health.”¹

On February 6, 2019, after more than five hours of deliberation, the jury found Harris guilty of first-degree murder and child endangerment resulting in death.¹

Life Sentence Without Parole

Chickasaw County District Court Judge Richard Stochl sentenced Harris on February 19, 2019. Under Iowa law, first-degree murder is a Class A felony carrying a mandatory sentence of life in prison without the possibility of parole or probation. The only avenue to release for someone serving that sentence in Iowa is a pardon or commutation by the governor.⁵

Before sentencing, Judge Stochl denied a defense motion for a new trial. Harris’s attorney Aaron Hawbaker argued the evidence did not support first-degree murder under Iowa law. Assistant Attorney General Denise Timmins responded that death from “severe diaper rash, starvation and dehydration” met the state’s torture-and-cruelty standard, and the judge agreed. The child endangerment conviction was merged with the murder conviction at sentencing.⁶⁷ Harris declined the judge’s offer to address the court.

The Appeal

Harris appealed to the Iowa Court of Appeals in Case No. 19-0299, raising two main arguments. She contended that the trial court should have permitted her expert witness, psychologist Dr. Michael O’Hara, to testify about her mental impairments in a way that could negate the intent element of the charges. She argued the first-degree murder jury instructions “heightened” the intent requirement, potentially opening the door to a diminished responsibility defense even though Iowa law generally forecloses that defense for general-intent crimes.⁸

She also argued her trial attorney had been ineffective for failing to pursue a diminished responsibility defense and for failing to object when prosecutors attacked her mental health evidence in closing argument while she was barred from formally presenting it.⁸

On January 21, 2021, a three-judge panel affirmed the conviction and sentence. Judge Anuradha Vaitheswaran, writing for the court, held that Harris had not preserved her claim on the expert testimony because she had affirmatively agreed at trial that she was not seeking a diminished responsibility instruction. The court wrote, “She cannot change horses in midstream.”⁹ On the ineffective-assistance claim, the panel held that trial counsel had no duty to pursue what it called an “unrecognized” defense under Iowa law and therefore did not breach an essential duty.⁸

Loss of Parental Rights to Her Daughter

Harris and Koehn also had a daughter who was nearly two years old when Sterling died. Child welfare authorities removed the girl from the Alta Vista home in August 2017. A hair test came back positive for methamphetamine, as did tests on both parents, and a juvenile court deemed her a “child in need of assistance.”¹⁰

Harris’s parental rights were later terminated. She argued on appeal that her inability to post bail in the murder case had prevented her from participating in the Department of Human Services programs required for reunification. The Iowa Court of Appeals upheld the termination, finding that her life sentence meant she would not be available to serve as a custodial parent. The court also noted that Harris did not challenge the underlying grounds for termination.¹⁰

Where Harris Is Now

Harris remains incarcerated in the Iowa Department of Corrections, serving her mandatory life sentence. On March 28, 2024, she filed a postconviction relief petition in Case No. PCCE090014, centered on a dispute over lost earned time and disciplinary reports on her prison record. The State restored the earned time and expunged the disciplinary reports, then moved for summary judgment on mootness grounds. As of June 2025, the case remained pending before the Iowa District Court for Polk County, with Harris opposing the State’s motion.¹¹ The filing does not challenge her underlying conviction or sentence.

Zachary Koehn’s Separate Case

Sterling’s father was tried and convicted separately. After a six-day trial in October and November 2018, a jury found Zachary Koehn guilty of first-degree murder and child endangerment resulting in death. His defense was that he was unaware of Sterling’s condition because he worked 70 to 80 hours per week as a truck driver and relied on Harris as the primary caretaker. Prosecutors countered with work logs showing fewer hours than he claimed, testimony about the small apartment, and expert witnesses who said the neglect had been obvious for ten to fourteen days. Koehn received the same mandatory life sentence, and the Iowa Court of Appeals affirmed his convictions on November 4, 2020.¹²¹³

1
Des Moines Register. Cheyanne Harris Iowa Mother Murder Trial
2
ABC30. Baby Died of Diaper Rash, Prosecutor Says
3
Fox 6 Now. Parents Charged With Murder, Infant Found Severely Underweight, Infested With Maggots
4
Des Moines Register. Iowa Baby Death: His Uncle Describes Short Life
5
Iowa Legislature. Iowa Criminal Sentencing Framework
6
New Hampton Tribune. Harris Gets Life Sentence
7
Waterloo-Cedar Falls Courier. Cheyanne Harris Sentenced to Life in Prison for Infant Son’s Death
8
Findlaw. State v. Harris, No. 19-0299
9
Des Moines Register. Cheyanne Harris Case: Iowa Mother Loses Appeal
10
Waterloo-Cedar Falls Courier. Cheyanne Harris Loses Parental Rights to Daughter
11
ACLU of Iowa. Harris Postconviction Relief Filing
12
Findlaw. State v. Koehn, No. 18-2216
13
Iowa Courts. State of Iowa v. Zachary Paul Koehn, No. 18-2216