The Supreme Court of Canada has given Robert Pickton more scope in his coming appeal to try to overturn his conviction on six counts of murdering women from Vancouver's Downtown Eastside.

The Port Coquitlam pig farmer was found guilty of second-degree murder by a B.C. Supreme Court jury in 2007 in the deaths of the six women and the B.C. Court of Appeal last June upheld the decision in a 2-1 split ruling.

An appeal to Canada's high court has never been in doubt – it's automatically granted because one of the B.C. appeal court judges had dissented, arguing an error in the trial judge's instructions to the jury led to a miscarriage of justice.

But the Supreme Court's decision to allow broader grounds to appeal means Pickton's lawyers won't be limited to arguing the objections lodged by the dissenting lower court judge.

That judge found prosecutors were improperly allowed to present twin options to the jury – that Pickton acted alone, while also raising the possibility others acted in concert with him and that he could still be convicted on that basis.

The decision was released Thursday morning without accompanying reasons.

Pickton was sentenced to life in prison with no chance of parole for 25 years after a year-long trial.

The appeal process has divided families of the victims, who find themselves torn between the potential outcomes.

Families of the six victims Pickton is convicted of killing – Sereena Abotsway, Mona Wilson, Andrea Joesbury, Brenda Wolfe, Georgina Papin and Marnie Frey – want the appeal to fail, ending any chance of his release.

Some others, whose loved ones are among the 20 more victims who Pickton was charged but never tried for killing, as well as still others for whom no charges are yet laid, hope a new trial is ordered that leads to convictions on many more counts to bring them closure as well.

More than 60 women, most sex-trade workers, went missing from the drug-ravaged Downtown Eastside from the mid-1990s until Pickton was arrested in 2002 after police raided his property.

Forensic investigators found blood samples, bone fragments, DNA samples and victims' possessions in a massive 20-month search of the farm.

The appeal is scheduled to begin in March.

Slideshow: The Victims