Suspects Arrested Following Months-long Homicide Investigation

Published on April 09, 2026

Two Cheyenne residents have been arrested following a months-long investigation into the death of their 4-month-old infant.

On August 8, 2025 at approximately 5:45 p.m., a Cheyenne Police Officer was dispatched to Cheyenne Regional Medical Center. Hospital staff reported that a male infant had been brought in by his parents, Joseph Hanson, 24, and Juliette Martinez, 23, after experiencing a seizure. Following an assessment, it was determined the baby required advanced medical care at Denver Children’s Hospital. When staff were unable to locate or contact the parents to obtain consent for the life-flight, the responding officer went to their residence to connect them with hospital personnel.

The following day, medical evaluations in Denver revealed extensive injuries. Doctors confirmed the infant had fractures and life-threatening brain trauma, which appeared to be the result of physical abuse. The child was placed on life support.

On September 8, 2025, the child was removed from life support and pronounced deceased.

On March 20, 2026, detectives received the completed autopsy report from the Adams and Broomfield County Coroner’s Office. The Chief Coroner determined the cause and manner of death to be homicide.

Detectives submitted probable cause affidavits to the District Attorney’s Office for the arrest of Hanson and Martinez. On April 8, both were arrested without incident and booked into the Laramie County Jail on charges of first-degree murder and aggravated child abuse.

This case remains under investigation by the Cheyenne Police Department.