Cheyenne Parents Arrested in Death of 4-Month-Old Infant

Two Cheyenne residents have been arrested and charged with first-degree murder and aggravated child abuse following the death of their four-month-old son.

Joseph Hanson, 24, and Juliette Martinez, 23, were taken into custody without incident on April 8, 2026, and booked into the Laramie County Detention center, according to reports from the Cheyenne Police Department.

During their initial appearances on the afternoon of April 9, 2026, in Laramie County Circuit Court, Judge TJ Forewood set the bond for each parent at $500,000 cash only. While booking sheets listed charges of both first-degree murder and aggravated child abuse, court records indicate that only the murder charges were referenced during the initial court proceedings.

Timeline of Events

The investigation into the infant’s death began on August 8, 2025, when an officer responded to the Cheyenne Regional Medical Center. Court documents state the parents brought their son to the hospital for treatment after the infant suffered a seizure.

According to court documents, the child was found having a seizure at approximately 11:30 a.m. On August 8, but was not brought to the medical center until 12:17 p.m. The parents left the facility at approximately 3 p.m., at which time Hanson informed staff he would return soon. By 5:48 p.m., Hanson had not returned and staff members were unable to reach him by phone, leading to the dispatch of a Cheyenne Police officer at 5:45 p.m.

The infant was subsequently airlifted to Denver Children’s Hospital for advanced medical care. Medical personnel in Denver evaluated the boy and discovered extensive injuries, including fractures and life-threatening brain trauma. Doctors determined these injuries appeared to be the result of physical abuse, and the child was placed on life support.

The infant remained on life support for one month before being removed from the system and pronounced deceased on September 8, 2025.

Investigation and Autopsy

The Cheyenne Police Department conducted a months-long investigation into the death. On March 20, 2026, detectives received a completed autopsy report from the coroners’ offices of Broomfield and Adams counties in Colorado.

The autopsy results determined that the cause of death was homicide. Following the review of the autopsy, detectives submitted probable cause affidavits to the District Attorney’s Office, leading to the arrests of Hanson and Martinez on April 8, 2026.

The suspects are presumed innocent until proven guilty in a court of law. The case remains under investigation by the Cheyenne Police Department.