The case of a Barrie, Ont., mother accused in the slaying of her two young children is being called a "catastrophic failure of the system" by the father's family.

Three-year-old Sophia and one-year-old Serena were found dead Wednesday in the fourth-floor apartment where they lived with their 31-year-old mother Frances Elaine Campione.

Frances Elaine Campione made her first court appearance Thursday, and was remanded into custody.
(CBC)

Frances Campione has been charged with two counts of first-degree murder.

Those who knew the family said Campione and her estranged husband, Leonardo Campione, had a strained relationship and were in the midst of a bitter divorce and custody battle.

Since they separated, Leonardo Campione has been living in Woodbridge, just north of Toronto, with his parents.

Father faced assault charges

Court documents show that he was charged with four counts of assault, one count of assault causing bodily harm and a single account of uttering threats.

Police have indicated that some of the charges involve the wife. He has not been convicted of any of the charges.

A written statement released to the media Thursday by the father's family calls it a time of "great sorrow."

The family refused to speculate on the deaths of their "beloved angels," saying they don't want to interfere with the court process. 

"We look forward to the public processes that will determine guilt and the inquest which will examine the catastrophic failure of the system and processes that should have protected the children it was meant to serve," the statement said.

Memorial grows at housing complex

Meanwhile, residents of the small city passed by the public housing complex in the northwest part of the city where the children lived and placed flowers on a growing memorial.

A resident of the apartment building where three-year-old Sophia and her one-year-old sister Serena lived places flowers on a growing memorial for the girls.
(CBC)

The double slaying has sent shockwaves through Barrie, a city that is an hour's drive north of Toronto that experiences few homicides. The children are the city's second and third homicide victims of the year.

Police have not yet revealed the cause of death of the two girls. Autopsy results are expected Friday.

The mother made her first appearance in court Thursday and was remanded in custody.

She will make her next appearance on Oct. 11 via video link from the Central North Correctional Centre in Penetaguishene where she is being held.