THORNTON, Colo. -- An 18-year-old man was arrested after his girlfriend's 3-month-old died Monday night in a case of suspected child abuse, the Thornton Police Department said.
Police arrested Isaiah Marquez for investigation of child abuse knowingly and recklessly causing death.
Marquez is the mother's boyfriend and is not the child's father, police said. He was booked into the Adams County Detention Facility.
Officers were called to the 9100 block of Gale Boulevard about 10:15 p.m. on a report of a child not breathing and unconscious.
The child was taken to a hospital and was pronounced dead. Hospital staff described the injuries the child suffered as nonaccidental trauma.
The Adams County Coroner's Office will perform an autopsy and determine cause of death.
The case remains under investigation. The child's name and gender were not released.