A Henry County jury on Tuesday convicted the father of an infant who was found dead in a maggot-infested diaper of murder and child endangerment.

Zachary Paul Koehn, 29, was found guilty in the August 2017 death of his son, Sterling Koehn, who was not yet four months old. The baby was found dead on a mechanical swing in a bedroom, weighing only a few ounces more than when he was born.

Koehn will be sentenced to life without parole at a later date. The boy's mother, Cheyanne Harris, 21, whose trial is pending, pleaded not guilty to the same offenses.

In opening statements, prosecutors described the last days of Sterling's life in graphic detail. Feces in his diaper ate through his skin, allowing E. coli bacteria in his diaper and in his stool to enter his bloodstream and cause an infection, authorities said.

The hot room attracted flies, which laid eggs that hatched into maggots while Sterling was alive; they crawled in his clothes and his diaper for days, prosecutors said.

The infant, weighing just under seven pounds, died of malnutrition, dehydration and infection. Autopsy photographs appeared to show the boy — wearing camo pants and a shirt with a cartoon cow above the words "let's play" — bleeding from the mouth.

Koehn called 911 on Aug. 30, 2017, and lied to the dispatcher, saying Sterling had died of sudden infant death syndrome, authorities said.

"This was not an accident," Assistant Iowa Attorney General Coleman McAllister said. "That was a cover story concocted by this defendant to cover the awful truth."

When he took the stand in his own defense, Koehn blamed the baby's mother, saying he "put his trust in the wrong person." But under cross-examination from the prosecutor, Koehn admitted he took better care of his dog than he did the infant.

During the week-and-a-half or more that Sterling was left in his swing, the couple continued to clothe and feed their 2-year-old daughter, McAllister said. The girl was in good health when law enforcement arrived at the family's Alta Vista apartment.

Koehn's attorney, Les Blair, has said Sterling's death was "a tragedy, not a crime." Blair urged the jury at opening statements to avoid a rush to judgment.

The jury in Mount Pleasant deliberated for about an hour before rendering the verdict, a reporter with the Waterloo-Cedar Falls Courier tweeted from the courtroom. The trial was moved to Henry County because of pretrial publicity in Chickasaw County.

A forensic entomologist examined the insects on Sterling's body and concluded the baby had been in his swing for nine to 14 days in the same diaper, authorities said.

When Chickasaw County sheriff's deputies arrived at the home, they found the deceased boy in a bedroom separate from where Koehn, Harris and their older child slept. Photographs show the child, his eyes open and his fists clenched, in the swing.

"He let Sterling rot in that room," Assistant Attorney General Denise Timmins said in court, according to the Courier. "He left him there to die."

The case was not one of the parents not having adequate resources to care for their children, prosecutors said. Koehn made $45,000 a year and had access to health insurance as a truck driver who hauled chickens from Wisconsin to Charles City, Iowa.

One of Koehn's former friends testified he was aware Koehn had a young daughter because he would often talk about her. But the friend said he did not know Koehn had an infant son, despite having visited his apartment.

Court records show the child's mother may use intoxication as a defense at her trial, which has not been scheduled. She reported last using meth two to three weeks before Sterling's death; diminished responsibility may also be used.

The state medical examiner ruled the boy's death a homicide. His cause of death was listed as failure to provide critical care.

The Associated Press contributed to this report.

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