Charges against a mother accused in the scalding death of her 18-month-old toddler have been upgraded to murder, police confirmed Tuesday.

Det. Sgt. Dan Sheppard said charges against the 22-year-old mother have been upgraded from aggravated assault to second-degree murder in the death of Miguel Fernandes.

Sheppard said autopsy results prompted the upgrade to the charges. The cause of death is listed as complications due to submersion-type burns.

"Being scaled like that and the pain and suffering that he must have went through was just a terrible thing. As a police officer, someone has to talk for him now," Sheppard said Tuesday outside a Finch Avenue courthouse.

The Catholic Children's Aid Society has launched an independent investigation against the mother but would not comment on the nature of the case.

Homicide investigators declined to comment on whether the mother had a history of mental illness.

Last week, police were called to a Jane Street and Lawrence Avenue apartment when a neighbour heard a child screaming uncontrollably.

Officers located the boy suffering from "obvious signs of trauma."

The baby was rushed to the burn unit at the Hospital for Sick Children, where he later died of his injuries.

A family friend, who requested anonymity, said the child's death was an accident.

The friend told CTV News the young mother boiled water to soak her hair before braiding it and accidentally dropped the scalding water on the child.

Melissa Alexander has been charged with second-degree murder. Alexander lived with her common-law husband. Both parents were at home during the incident.

Alexander appeared in court on Tuesday.

With a report from CTV's Chris Eby