Medical examiner: Alta Vista baby severely underweight at death

MOUNT PLEASANT (AP) — A medical examiner testified Thursday that a 4-month-old found dead in a baby swing last year weighed only a few ounces more than his birth weight at the time of his death.

The testimony occurred during the murder trial of the baby’s father, 29-year-old Zachary Paul Koehn, who also faces a child endangerment count in the August 2017 death of his son, Sterling Koehn, in their Alta Vista apartment.

Cheyanne Harris, the child’s mother, is also charged and faces a separate trial.

Dr. Dennis Klein, chief medical examiner for the state, said the baby weighed just under 7 pounds during the autopsy, the Waterloo Courier reported. Klein said the boy should have weighed about 11 pounds.

“Nothing natural would have done this,” Klein said.

Klein laid out graphic details of the baby’s suffering in the last days of his life — details that contradicted Koehn’s statements that he had played with the baby and had heard him crying the day before his death.

Klein said the infant was so dehydrated and ill that he would not have been able to cry or respond to stimuli. He said he was unable to determine a time of death or even a range of time, and it was possible the baby had died Aug. 30, 2017, the day he was found by medical responders answering a 911 call placed by Koehn.

Timothy Huntington, a forensic entomologist, testified regarding fly larvae that had been found on the baby’s clothes.

He said the scuttle fly larvae had been attracted to the odor of feces and urine, and had fed on the feces and other fluids in the boy’s diaper, not on the baby’s skin.

Huntington said the presence of the scuttle flies — small brown flies that are attracted to garbage — could not determine the time of death, only that Sterling had been in the same diaper from nine to 13 days.

He said the lack of other insect activity made it unlikely Sterling had been dead for more than a day.

Other testimony Thursday came from members of Koehn’s family as the defense started to present its case.

Family members testified Koehn was originally from California and had been adopted by a Mennonite family as an infant. The family moved to the north Iowa area when Koehn was young.

Koehn’s father said Zachary Koehn graduated from the Mennonite school at age 14 after finishing eighth grade, which is typical for the community. He said Koehn was excommunicated from the faith at age 16, something that Koehn had told investigators was because of drinking.

Other relatives said Koehn had an older son, but Koehn had given custody of the boy to Koehn’s parents because of mental health issues with his then-wife, the boy’s mother (not Harris).

Koehn’s trial was moved from Chickasaw County to Henry County to counter pretrial publicity in the case.