TORONTO -- Prosecutors say a woman accused of killing her stepdaughter failed in her duties as a parent when she allowed the child to go without food, water and medication over a considerable period of time.

Crown lawyer Anna Tenhouse is making the assertion in closing arguments at the trial of Elaine Biddersingh, who has pleaded not guilty to first-degree murder in the death of 17-year-old Melonie Biddersingh.

The girl's body was found in a burning suitcase in an industrial parking lot north of Toronto in 1994 but went unidentified for years until 2011, when Biddersingh told an Ontario pastor the girl had "died like a dog."

Melonie came to Canada from Jamaica in 1991 with two brothers to live with her father and her stepmother in Toronto.

Tenhouse says Melonie and her siblings were scared of Biddersingh, who was the "mastermind" of the physical and emotional abuse they suffered.

Tenhouse says Biddersingh wanted the children to be her slaves.

"Elaine failed Melonie. She did not protect her as she had promised," Tenhouse said. "Elaine played a role in everything that happened in that apartment."

The trial has heard that Melonie was deprived of food, confined, beaten and emotionally abused.

The trial also heard that Melonie's father, Everton Biddersingh, was found guilty in January of first-degree murder in his daughter's death, but they were instructed to disregard that conviction as "completely irrelevant" to the case before them.

"Everton never initiated a beating unless it was about something Elaine complained about," Tenhouse said. "Melonie seemed to get the worst of the punishments."

Medical evidence called in the trial indicated Melonie drowned or nearly drowned, inhaling water shortly before her death. It also indicated she was severely malnourished and had 21 healing fractures at the time she died.