TORONTO -- A woman accused of killing her 17-year-old stepdaughter more than two decades ago was found guilty of second-degree murder on Monday after a trial which heard graphic evidence of the physical and emotional abuse suffered by the girl.

Elaine Biddersingh, who had been charged with first-degree murder, had pleaded not guilty in the death of Melonie Biddersingh, whose charred, malnourished body was found in a burning suitcase in an industrial parking lot north of Toronto in 1994.

The teen's body went unidentified for years until 2011, when her stepmother told an Ontario pastor the girl had "died like a dog" after being confined and denied food and medication.

"This was a very long and difficult trial," Crown prosecutor Mary Humphrey said outside court after the verdict, which was reached following six days of deliberations. "Justice was delivered today."

The conviction carries an automatic sentence of life in prison with no chance of parole for at least 10 years.

Elaine Biddersingh, who had been out on bail throughout the trial, shook her head slightly after a juror read out her verdict. She then picked up a bible she'd brought into court with her and began to read.

When the judge presiding over the case ordered her into custody, Biddersingh smiled, embraced her youngest daughter, who had attended much of the trial, and then turned herself over to a court officer.

Outside court, Biddersingh's defence lawyers said their client was in shock.

"I don't believe she expected this verdict and I imagine she's trying to digest it," said Alana Page. "Probably what looked to be a smile was just a reflection of her being in shock."

Melonie's father, Everton Biddersingh, was found guilty in January of first-degree murder in his daughter's death.

Elaine Biddersingh's defence lawyers -- who did not put their client on the stand or call their own evidence -- suggested Melonie's father was to blame for her death, while his wife was a victim of domestic abuse.

"While no one would ever suggest that it wasn't terrible to live in that apartment, there was evidence as well that not only were the Biddersingh children victims, as I believe they were, but Elaine was a victim in her own right," Page said.

The defence team also noted Biddersingh's role in helping the authorities identify Melonie's remains years later.

"They would never have known that Melonie had died if Elaine hadn't have come forward. That never would have happened," said defence lawyer Jennifer Myers.

The defence team suggested at trial that Melonie died when her father held her head down a toilet in punishment, causing her to drown.

Exactly how Melonie died remains unclear but expert evidence at the trial has indicated she inhaled water shortly before her death and either drowned or nearly drowned, but died afterward from something else, such as starvation.

Crown prosecutors, however, argued that Biddersingh -- a religious woman -- was the mastermind behind the abuse suffered by Melonie, while her husband was the enforcer.

They suggested Biddersingh failed in her duties as a parent, noting that the woman believed Melonie was possessed by the devil and treated her stepdaughter very differently from her own children. They also argued she played "an active and substantial" role in Melonie's death.

The trial heard that Melonie came to Canada from Jamaica in 1991 with two brothers to live with her father and her stepmother in Toronto. The children, who had lived in extreme poverty, saw the move as a great opportunity that would lead to a brighter future.

But instead of being sent to school, the children were kept at home and were made to do their father and stepmother's bidding. Melonie in particular had to clean the house, wash clothes in a bathtub and was responsible for caring for Biddersingh's baby girl, the trial heard.

The trial heard that Melonie's younger brother died in an accident in 1992, and Melonie and Cleon's treatment worsened significantly over time, with Melonie getting the worst of the abuse.

The trial heard she was kicked, slapped and thrown against walls by her father, her stepmother once threw a mug at her head so hard it broke, she was deprived of food, made to sleep on the floor, confined to the apartment and eventually chained to the furniture.

As her condition worsened, the trial heard Melonie cried with pain, had trouble moving and was clearly in need of medical attention.

Medical evidence called in the trial indicated Melonie was severely malnourished and had 21 healing fractures when she died.