KINGSTON, Ont. - All of the evidence has now been heard in a trial of three people accused of killing half of their family over honour.

The last witness, a linguistics and Afghani cultural expert, testified today for the defence in the Shafia family trial in Kingston, Ont.

Mohammad Shafia, 58, his wife Tooba Yahya, 42, and their son Hamed, 21, are on trial and have each pleaded not guilty to four counts of first-degree murder.

They're accused of killing Shafia sisters Zainab, 19, Sahar, 17, and Geeti, 13, as well as Shafia's first wife in a polygamous marriage.

Their bodies were found June 30, 2009, in a car submerged in a canal in Kingston, where the family had stopped on their way home to Montreal from a trip to Niagara Falls.

Since the trial began Oct. 20, the jury has heard from about 60 witnesses and has seen more than 160 exhibits.

Closing arguments are set to start Monday, and the judge told the jury he hopes to have them start deliberating on Wednesday.