BRAMPTON, Ont. -- A father and stepmother accused of killing the man's 10-year-old son could both be found guilty of murder even if only one of them carried out the beating that triggered the boy's death, jurors heard Thursday.

An Ontario Superior Court judge began his final instructions to the jury weighing the case of Garfield Boothe and his wife Nichelle Boothe-Rowe. Deliberations are expected to begin Friday afternoon.

The couple is charged with second-degree murder in the death of Shakeil Boothe, whose battered and emaciated body was found in the family's Brampton, Ont., home on May 27, 2011.

Justice Fletcher Dawson told jurors that while both accused were charged and tried together, each should be considered separately when it comes to the verdict.

Each can be found guilty of second-degree murder, guilty of manslaughter or not guilty, he said.

To reach a verdict of murder, the jury must find the accused had the intention to kill Shakeil or to cause bodily harm they knew would probably cause him to die, Dawson said.

For manslaughter, they must only find that the accused committed an unlawful act -- such as assault or failure to provide the necessaries of life -- that led to Shakeil's death, he said.

A person can be found guilty of an offence if they helped or encouraged another person to commit it, or if they were involved in a common unlawful purpose knowing it would likely lead to the other offence, the judge said.

In Boothe-Rowe's case, the jury must also consider whether she was under duress at the time, he said.

Her lawyer Brian Ross has argued she didn't stop her husband from abusing Shakeil because she feared for her own life after years of domestic violence.

Court has heard Shakeil died "minutes to hours" after being savagely beaten. The pathologist who examined him said the attack caused widespread internal bleeding that his weakened body could not recover from.

Dr. Michael Pollanen stressed, however, that Shakeil had already been on a "downward spiral" due to advanced malnutrition, injuries of various ages and severe infection that had spread through his blood into his lungs.

The combination proved fatal, he said.

No one witnessed the final attack and both Boothe and Boothe-Rowe have denied committing it.

Therefore it's up to the jury to decide whether either one delivered the blows and, if yes, whether the other aided or abetted by failing to stop the abuse or by taking part in another offence that led to the attack, Dawson said.

Boothe admitted on the stand he regularly beat his son with a belt for discipline, while his wife admitted she did not do enough to protect the boy. Both said they denied Shakeil much-needed medical care out of fear someone would notice his injuries.

Jurors also heard they can't use the couple's "bad character traits" to convict them.

Court has heard testimony painting Boothe as a violent, controlling man who regularly consumed marijuana and once pleaded guilty in a domestic assault case.

Dawson told jurors not to let character flaws or previous offences colour their analysis of the evidence.

But he said it would be different if they made a finding that there was a "pattern of similar conduct toward the same victim" -- for example, if someone had shown a propensity to discipline Shakeil in the family home.

In that case, Dawson said, the jury could choose to infer that the behaviour continued.

The judge will continue his instructions Friday before the jury is sequestered.