DNA matches from two of the women Robert William Pickton is accused of killing were found on the Pickton farm, jurors in his murder trial were told Tuesday.

Yvon de Moissac, who analyzed DNA results during the investigation of the Pickton property that began in February 2002, said a DNA profile matching Sereena Abotsway was found on a black see-through shirt in the closet of Pickton's bedroom in the trailer where he lived.

De Moissac also testified in B.C. Supreme Court in New Westminster that an orange plastic bag in the slaughterhouse, where the remains of Mona Wilson were found, yielded DNA matching Andrea Joesbury.

Pickton is charged with six counts of first-degree murder in the deaths of Abotsway, Wilson, Joesbury, Marnie Frey, Georgina Papin and Brenda Wolfe.

The B.C. pig farmer faces charges of murdering 20 other women who also went missing from Vancouver's Downtown Eastside, but will stand trial for those charges at a later date. He has pleaded not guilty to all charges.

DNA on apron at slaughterhouse

Jurors also were told Tuesday that 30 items, consisting mostly of clothing, had DNA belonging to Dinah Taylor, one of the three people arrested in connection with the case, but who was never charged.   

The DNA of Pat Casanova, who was also initially arrested but never charged, was found on a rubber apron in a building known at the slaughterhouse, court was told. His DNA and the DNA of Pickton were also on a pair of night vision goggles located in the farmer's home, de Moissac testified.

Under cross-examination by defence lawyer Marilyn Sandford, de Moissac acknowledged the match for Joesbury was only one of 269 swabs for DNA taken from the bag.

Sandford also challenged de Moissac about the techniques used to gather DNA evidence.

Sandford referred to the neck of a broken glass bottle found in a motor home that had yielded the DNA of Wilson. Sandford asked why only a single swab from that bottle was sent to the lab when many swabs are often taken from other exhibits.

De Moissac said gridding — where an exhibit is divided into small squares and each of those is then examined — was initially not an option.

Swabbing stains could be 'waste' 

De Moissac said he was operating under the normal protocol of sending one swab from a representative stain. 

"You agree, sir, that if, for example, this bottle were used as a weapon, it might be that perpetrator DNA could be found elsewhere, such as on the base of the bottle if it were swabbed?" Sandford asked.

"That's possible," de Moissac replied.

Later, in discussing his examination of some blood-stained runners also found in Pickton's motorhome, search witness Jonathan Faris said he only sent the swab of one stain. 

He said the runners had been looked at by a blood-spatter expert and he believed the blood came from one event, so it could be a "waste of resources" to swab every stain. 

Sandford suggested that swabbing every stain would have given a fuller picture of the forensic significance of the runners. 

"I have to admit maybe a more comprehensive search should have been done in this case," Faris said. "But at the time, I was proceeding as I would in a standard case."

But Faris later said that as the investigation proceeded, gridding was done on exhibits.

With files from the Canadian Press