It took less than a day for Robert Pickton's defence team to announce they will appeal the serial killer's murder convictions to the Supreme Court of Canada.

The B.C. Court of Appeal upheld the Port Coquitlam pig farmer's 2007 conviction on six counts of second-degree murder in a split decision released Thursday.

Defence lawyer Gil McKinnon confirmed today Pickton will appeal the case to the country's high court on the basis of the dissenting opinion of Justice Ian Donald, who concluded there was a miscarriage of justice requiring a new trial.

He was overruled by the other two appeal court judges, but because of the split ruling the Supreme Court of Canada must automatically hear Pickton's appeal.

Had Thursday's appeal decision been unanimous, he would have had to seek and be granted leave from the top court for the appeal to be heard.

Pickton was found guilty of second-degree murder in the deaths of Sereena Abotsway, Mona Wilson, Andrea Joesbury, Brenda Wolfe, Georgina Papin and Marnie Frey.

He was sentenced by B.C. Supreme Court Justice James Williams to the maximum of life imprisonment with no chance of parole for 25 years.

Williams had split the case and tried Pickton on those six charges, setting aside 20 other counts involving other missing women whose DNA was found at the farm.

A new trial on all 26 counts could happen only if the Supreme Court of Canada overturns the convictions relating to the six.

Justice Donald in his dissenting opinion found Williams wrongly reinstructed the jury at one point during their deliberations, introducing a new way to convict Pickton if they found he was an "active participant" in the killings but didn't act alone.

Donald said the trial judge failed to properly instruct the jury on the law involving aiding and abetting a crime.

He noted Crown prosecutors spent much of the trial and their final arguments rejecting defence suggestions others with access to the farm committed the murders and stuck to their scenario that Pickton acted alone.

"By leaving open aiding and abetting, the judge permitted the Crown to take advantage of an alternate route to liability without suffering any loss of credibility in its sole perpetrator theory," Donald found.

"The Crown did not have to ride two horses at once, on the one hand putting a case that Pickton alone killed the victims, and on the other, explaining who might have been the other killer or killers and what they did."

Although the Crown case was "powerful" based on Pickton acting alone, Donald said, "the prospect of others involved was always present" and the jury should have been properly instructed at the outset.

He said six days into jury deliberations – when jurors asked if they could convict if they felt Pickton acted "indirectly" – was too late to revise the law guiding them.

Donald noted the jury reached the "somewhat curious result of second-degree murder" – suggesting their verdict stemmed from confusion or frustration rather than the evidence.

The two other appeal court justices found Williams' new instructions corrected his earlier error and the convictions should stand.

The jury handed down the guilty verdict on the 10th day of deliberations.

Family members of some victims say they hope Pickton will win the appeal, be granted a new trial on all 26 charges and then be found guilty of first-degree murder on all counts.

The second group of victims Pickton is charged with killing are: Tiffany Drew, Sherry Irving, Diana Melnick, Wendy Crawford, Inga Hall, Tanya Holyk, Angela Jardine, Heather Bottomley (of New Westminster), Jennifer Furminger, Patricia Johnson, Debra Jones, Diane Rock (of Abbotsford), Sarah de Vries, Cara Ellis, Kerry Koski, Jacqueline McDonell, Andrea Borhaven, Cynthia Feliks, Helen Hallmark and Heather Chinnock (of Surrey).

A new trial in the case would mean selecting a new jury that might need years to weigh a huge mountain of evidence – far more than was heard at the first trial.

Pickton's own words presented at the trial suggested he is responsible for killing many more missing women beyond the murders for which he's charged.

The trial included videotape evidence in which Pickton told an undercover officer posing as a cellmate that he planned to do "one more" to make it "an even 50."

Jurors heard gruesome evidence involving the discovery of remains of several women on the Pickton farm property and the testimony of one witness who said she saw a dead woman hanging in the slaughter house.

Pickton admitted to police women's remains were at the farm but he denied killing them.

More than 60 women, many of them sex trade workers, went missing from Vancouver's drug-ravaged Downtown Eastside from the mid-1990s until Pickton was arrested in 2002, when police raided his property.

It launched a massive 20-month search of the farm, where forensic investigators found blood samples, bone fragments, DNA samples and victims' possessions.

Related:

• Conviction of serial killer Pickton upheld in split ruling

• Mixed emotions torment families in wake of Pickton appeal ruling