A death investigation is underway after a 4-week-old baby boy died in Yucca Valley.

Mesa police officials say that later, investigators learned the baby's father, 22-year-old Jonathan Enriquez, was alone with the child when she stopped breathing.

A 22-year-old Arizona father is facing the possibility of life in prison after police say he brutally beat his 4-week-old daughter to death because she was crying.