CHEYENNE — The parents of a 4-month-old boy accused of abusing the infant and causing his death in August 2025 were arrested Wednesday on suspicion of first-degree murder.
Joseph Hanson, 24, and Juliette Martinez, 23, were taken into custody without incident Wednesday and booked into the Laramie County Detention center on charges of first-degree murder and aggravated child abuse, the Cheyenne Police Department (CPD) reported Thursday morning.
“Detectives submitted probable cause affidavits to the District Attorney’s Office for the arrest of Hanson and Martinez,” the report says.
As of Thursday morning, the supporting charging affidavits hadn’t yet been filed with the Laramie County District Court.
However, Cheyenne police say their investigation began Aug. 8, 2025, when an officer responded to Cheyenne Regional Medical Center after receiving a report of an infant boy who had been brought in by his parents after having a seizure, the agency’s Thursday report says.
“Following an assessment, it was determined the baby required advanced medical care at Denver Children’s Hospital,” the CPD reports. “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.”
After the 4-month-old had been transported to the Denver hospital, medical personnel who evaluated the boy found he had “extensive injuries,” the report says.
“Doctors confirmed the infant had fractures and life-threatening brain trauma, which appeared to be the result of physical abuse,” the report continues. “The child was placed on life support.”
A month later on Sept. 8, 2025, “the child was removed from life support and pronounced deceased,” the report says.
Months later, on March 20, 2026, CPD detectives received a completed autopsy report on the 4-month-old from the coroners’ offices of Adams and Broomfield counties in Colorado.
In that report, the chief coroner “determined the cause and manner of death to be homicide,” according to the Cheyenne police report.
This is a developing story that will be updated as more information is available.
Greg Johnson can be reached at greg@cowboystatedaily.com.
