Mom Who Let 7-Month-Old Baby Die Convicted of First-Degree Murder

On June 11, 2023, Sheyenne Shore brought her 7-month-old daughter to a hospital in Story County, Iowa. The baby was cold, stiff, and unresponsive, with fixed and dilated pupils. Doctors worked to save the baby. They were unsuccessful. On April 2, 2026, a central Iowa jury convicted Shore, 26, of first-degree murder and child endangerment resulting in death. The verdict came nearly three years after the infant’s death.

What Shore Told Investigators

When officers arrived at the hospital, Shore told them the baby had struck its head on toys. She said she had no other knowledge of how the baby had been injured. Court documents show investigators found that account inconsistent with the infant’s condition and the physical evidence at the scene.

The baby’s father, Juan Montalvo Jr., had already faced charges in connection with the child’s death. He pleaded guilty in a separate case to child endangerment resulting in serious injury and was sentenced to 10 years in prison in 2025. Shore originally faced the same set of charges as Montalvo. Prosecutors pursued the first-degree murder charge against her, and the jury agreed.

The Conviction

The jury returned its verdict on April 2, 2026, finding Shore guilty on both counts - first-degree murder and child endangerment resulting in death. First-degree murder in Iowa carries a mandatory sentence of life in prison without the possibility of parole. Shore’s sentencing date had not been formally announced at the time of reporting, but the conviction leaves no judicial discretion on the sentence. Shore was 23 years old at the time of her baby’s death. She was 26 when the jury delivered its verdict.

A Pattern Prosecutors Presented

Throughout the trial, prosecutors presented evidence they said demonstrated Shore’s awareness of her baby’s condition and her choice not to seek timely help. The details of what the infant experienced in the hours before it was brought to the hospital were presented to the jury as the foundation of the first-degree murder charge - evidence of deliberate action, not accident or neglect. Montalvo’s earlier plea and sentencing established an additional layer of context for the jury, documenting that harm to the child had been acknowledged by at least one party before Shore’s trial began.

A Verdict Three Years in the Making

The case drew significant attention in central Iowa, both for the age of the victim and for the length of time between the baby’s death and the conclusion of the criminal proceedings against her mother. WOI and KCRG, which covered the trial throughout, reported that the jury reached its verdict after deliberation on April 2 - nearly three years to the day after the infant was brought to the hospital and could not be revived. Shore now faces a mandatory life sentence. Her baby was seven months old.

References: Central Iowa Mother Convicted of Murder in 7-Month-Old’s Death | Both Parents Now Convicted for Homicide of Story County Infant