Cheyenne Parents Accused Of Killing 4-Month-Old Plead Not Guilty, To Have Trials

A Cheyenne mother charged with murder in the death of her 4-month-old son pleaded not guilty this week, setting the stage for both parents to be tried for first-degree murder in separate trials. Juliette Martinez, 23, entered her plea Monday in Laramie County District Court. Her boyfriend and the child’s father, Joseph Hanson, 24, pleaded not guilty on April 30.

The criminal case began Aug. 8, 2025, when staff at Cheyenne Regional Medical Center contacted police after the baby arrived with severe injuries requiring emergency transport to Children’s Hospital Colorado. Hospital staff were reportedly concerned not only by the baby’s condition but because they were struggling to get consent from the parents to life-flight the infant.

According to an affidavit filed by Cheyenne Police Detective Mike Webster, Martinez told investigators she had been asleep until late that morning before noticing the baby’s breathing looked unusual. She said Hanson agreed the breathing was odd. The couple picked the baby up and tried to wake him before he began shaking. Martinez allegedly told police she recorded a video and sent it to Hanson’s mother, who urged them to go to the hospital immediately. Investigators noted the couple noticed something was wrong around 11:30 a.m. but did not take the baby to the hospital for roughly 45 minutes.

Hanson gave a different version, saying he had stayed awake with the baby during the night, fed him around 4 a.m., then left for work at about 7:30 a.m., leaving the infant in Martinez’s care. Police seized both parents’ cellphones. Martinez’s phone records conflicted with her statements about being asleep, showing activity on TikTok and Snapchat between 8:03 and 9:29 a.m. Police also detailed internet searches allegedly made after the baby showed signs of distress, including “Shaken baby syndrome symptoms,” “Signs father gave baby shaken baby syndrome,” and “Seizures in 5-month-old baby.” Investigators also reported “58 missing text messages” from Martinez’s phone during that morning.

A search warrant executed at the family’s home on Aug. 9 revealed several holes in the walls “about the size of an adult fist.” Hanson admitted to punching the holes before the couple’s other children returned home. Detectives also found shattered remains of a glass table.

The paternal grandmother reportedly told police that Martinez typically watched the children while Hanson was at work, but there were times she was allowed to pick up only the victim—not the other children—because Martinez “did not have a bond” with the boy. She also said she believed Martinez had been suffering from severe postpartum depression.

Medical findings from Children’s Hospital Colorado described severe swelling of the brain, oxygen deprivation injuries, bleeding on the brain, fractures in both legs, a spinal fracture, and a possible broken rib. Dr. Denise Abdoo reportedly told investigators the injuries were “consistent with child abuse.” A neurosurgeon described the infant’s condition as a “nonsurvivable” brain injury. On Sept. 2, 2025, doctors confirmed the baby was brain dead. He was removed from life support and died Sept. 8.

Hanson remains in jail on a $500,000 cash or surety bond but is barred from contact with minor children if released. Martinez is held on a $500,000 cash-only bond. Hanson’s jury trial is scheduled to begin Aug. 24. Martinez has filed a demand for a speedy trial; a date has not yet been assigned.