The lawyers of a Montreal couple and their son who were convicted on Sunday of murdering four female relatives are expected to appeal the decision.

A jury found Mohammad Shafia, 58, his wife Tooba Yahya, 42, and their son Hamed, 21, each guilty of four counts of first-degree murder in the deaths of Shafia's three teenaged daughters and his first wife.

A first-degree murder conviction carries an automatic life sentence with no chance of parole for 25 years.

Sisters Zainab, 19, Sahar, 17, and Geeti, 13, along with Shafia's other wife Rona Amir Mohammad, 52, were found dead on June 30, 2009 in a car at the bottom of a canal in Kingston, Ont.

On Sunday, after 15 hours of deliberation following the 10-week trial, jurors handed down their verdict.

"It was a very dramatic sceene inside the courtroom of course when the jurors stood up and said that all three accused were to be found guilty on all counts," said CTV's Montreal Bureau Chief Genevieve Beauchemin.

"Both the accused at the time -- now the convicted killers -- and jurors were very emotional."

In a rare move the defence lawyer asked each juror to stand up and say whether they agreed with the verdict. One female member of the jury said she did, but then sat down and immediately burst into tears, Beauchemin told CTV's Canada AM on Monday.

When asked by the judge whether they had anything to say, Mohammad, Tooba and Hamed all maintained their innocence -- a stance they took throughout the trial.

"We are not criminal, we are not murderers, we didn't commit the murder and this is unjust," Mohammad Shafia told the court through a translator.

"Your honourable justice, this is not just," Yahya said, also through an interpreter. "I am not a murderer, and I am a mother -- a mother!"

Hamed addressed the judge in English, saying: "Sir, I did not drown my sisters anywhere."

Hamed also leaned forward when the verdict was read, apparently upset, while his parents rubbed his back in an attempt to console their son.

After the verdicts were read out the crowd made its way outside to line up near a fence to catch one last glimpse of the convicted killers before they were taken away.

As Mohammad Shafia was led out, he loudly said: "Wrong," apparently in reference to the verdict.

Outside the courtroom, prosecutor Gerard Laarhuis said it was a good day for Canadian justice but also a sad day because it involved the death of four women.

"This jury found that four strong, viviacious and freedom-loving women were murdered by their own family in the most troubling of circumstances," he said.

Some onlookers in a crowd on the court steps cheered when Laarhuis spoke while others heckled the prosecutor.

"This verdict sends a very clear message about our Canadian values and the core principles of a free and democratic society that all Canadians enjoy and even visitors to Canada enjoy," Laarhuis said.

Also speaking outside the court, Shafia's lawyer Peter Kemp said he believes the jury was swayed by wiretap conversations in which his client called his dead daughters whores.

"He wasn't convicted for what he did," Kemp said. "He was convicted for what he said."

Hamed's lawyer, Patrick McCann, said his client will appeal. He believes Hamed's parents will do the same.

From the start of the trial in October, prosecutors argued these were "honour killings" -- the Afghan-Canadian family's answer to the young sisters' perceived shameful behaviour.

"It is difficult to conceive of a more despicable, more heinous, more honourless crime," Justice Robert Maranger said in court after the verdict was delivered Sunday.

"The apparent reason behind these cold-blooded, shameful murders was that the four completely innocent victims offended your completely twisted concept of honour...that has absolutely no place in any civilized society."

Prosecutors had argued that the young Shafia sisters had shamed the conservative Afghan family -- and especially its patriarch -- by wearing revealing clothing, refusing to don hijabs and having boyfriends.

The jury heard that Zainab had previously run away from home and was briefly married to a Pakistani man Shafia did not approve of. The marriage was annulled within 24 hours.

Sahar also had a forbidden boyfriend, while the youngest of the three, Geeti, told her teachers she wanted to be placed in foster care. Mohammad Shafia's first, infertile, wife had protected the girls, especially Sahar, whom she had been raising as her own, court heard.

Jurors reached the guilty verdict after a 10-week trial, 58 witnesses and 15 hours of deliberations.

Court also heard damning wiretapped conversations between the accused in which, at one point, Shafia said of his dead daughters: "God's curse on them … May the devil shit on their graves."

Teachers, child protection workers and police officers testified about reports from the girls that they were afraid of their father and brother and wanted to run away from home.

The Crown painted a picture of a highly dysfunctional polygamous family, with Shafia and Hamed exerting control over female members of the household and the two wives fighting for Shafia's affections.

Yahya and Shafia refuted the Crown's theory and evidence, saying they loved their children and would have never killed them. In interviews with police and on the stand, the couple maintained the deaths were a tragic accident.

Beauchemin said there will be no victim impact statement following the trial. She said that may be because relatives stood by the accused throughout the trial.

"Perhaps that's part of the issue here or perhaps simply all those people felt everything that needed to be said...had been said during the trial," Beauchemin said.