Ariz. toddler's death ruled homicide; 3 arrested

TUCSON, Ariz. -- The Pima County, Ariz., Medical Examiner's Office has ruled that the September death of a 22-month-old baby was a homicide, reports CBS affiliate Tucson News Now.

Three people have been arrested in connection with the case.

The autopsy found that Mia Castanon died on Sept. 11 of asphyxia at a daycare facility in Tucson.

The owner of the daycare, 31-year-old Daena Soto, and her husband, 32-year-old Ricardo Soto Jr., were arrested on Monday and appeared in court via video on Tuesday morning. Daena Soto was charged with one count of negligent homicide, and Ricardo Soto was charged with one count of tampering with evidence.

Fifty-five-year-old Guadalupe Soto, Ricardo's mother, was arrested on Sept. 11 and charged with one count of tampering with evidence.

After the child died, Soto family members allegedly began cleaning the residence before investigators arrived, according to police.

The blanket on which the baby was found unresponsive had allegedly been removed by Guadalupe Soto.