Aragon and Quintana, both of Jerome, are now charged with one count each of felony involuntary manslaughter for their roles in the girl's death. Both men also are charged with felony injury to a child.
Authorities said the girl and her 12-year-old brother, Bear, were with their father and Quintana on Dec. 25, when Aragon's car got stuck in a snow drift en route to the home of the children's mother.
In the criminal complaint, the prosecutor accuses Aragon and Quintana of allowing the children to walk to their mother's home while the adults tried to dislodge the car. Officials had said temperatures in the area at the time the girl was missing ranged from 27 degrees above zero to minus 5.
The children ultimately separated and never made it to their mother's house. The boy survived, but rescue crews found the girl the next day buried in snow. She was later pronounced dead, likely of hypothermia.
Aragon was arrested Dec. 26 and charged with second-degree murder and felony injury to a child. Quintana was arrested days later and charged with the same crimes. Aragon is being held on a $500,000 bond in the Jerome County Jail; Quintana is being held on a $150,000 bond in the Blaine County Jail, the Idaho Mountain Express reported.
Under Idaho law, the difference between second-degree murder and involuntary manslaughter is the level of intent, said Nora O'Callaghan, a criminal law professor at the University of Idaho.
"Involuntary is a case of showing indifference to the value of human life by your conduct," O'Callaghan said. "It's not like you wanted the person to die, but you should have been more protective of human life."
If convicted of involuntary manslaughter, the two men face up to 10 years in prison.