LONDON, Ont. - Testimony at the trial of the man accused in the murder of eight-year-old Victoria Stafford wrapped up Tuesday as Michael Rafferty's lawyer tried to undermine the Crown's key witness, but stopped short of putting his client on the witness stand.

WARNING: Graphic details from this court case may disturb some readers.

Dirk Derstine opened and closed the defence's case with a single witness -- a woman who was one of the last people to see Tori alive on April 8, 2009 -- in hopes of casting doubt on the assertion that Tori had been abducted at random.

The grandmother, whose name cannot be published, picked up her grandchildren from Oliver Stephens Public School in Woodstock, Ont., that day, and said she saw a woman matching Terri-Lynne McClintic's description go into the school.

Later, she said, she saw the same woman walking away with Tori -- an image now hauntingly familiar to anyone who saw the grainy surveillance video that showed what police believed to be the little girl's abduction in process.

"(She) seemed like she was on a mission," the woman testified, describing the woman in the white coat as having a "stern" look on her face.

"The little girl that was with her was happy, skipping, talking a mile a minute...I assumed the person that she was talking to might have been her mother."

McClintic has admitted to being the woman in the surveillance video. Over six days in March, she told a horrifying story of a drug-addled couple plucking a young girl at random out of a bustling end-of-day crowd of schoolchildren, using her for the man's sexual pleasure, then McClintic killing her with inconceivable brutality.

McClintic testified that Rafferty, then her boyfriend, urged her to kidnap a young girl and dropped her off outside the school. She said she chose Tori because she spotted her outside the school all alone.

During his cross-examination of McClintic, Derstine put forward a very different scenario of what happened April 8.

Describing her as a troubled young woman with a thirst for violence, he accused McClintic of orchestrating the kidnapping over a drug debt, then offering the child sexually to her boyfriend.

When he rejected the offer, she killed the girl, with Rafferty nothing more than a horrified bystander, Derstine posited.

Court was told Tori's mother Tara McDonald purchased the powerful prescription painkiller OxyContin from McClintic's mother on two occasions, though both denied having met each other more than in passing on those two occasions.

McClintic testified she did not know Tori, while McDonald also testified the two had never met. Nonetheless, McDonald's phone number was found in two places in the home McClintic shared with her mother.

During Tuesday's cross-examination, Crown attorney Michael Carnegie questioned the grandmother's memory of the events of that day -- specifically her recollection of the woman going into the school versus the woman walking with Tori.

Carnegie noted that when she saw the woman and the girl walking along the road outside the school it was a "fleeting glance" as she drove past.

Rafferty, 31, has pleaded not guilty to first-degree murder, sexual assault causing bodily harm and kidnapping in Tori's death.

The Crown wrapped up its case against Rafferty last week. Now the defence has finished, it paves the way for closing arguments to begin.

Jurors were told Derstine will present his final arguments on Friday, the Crown will close on Monday and the judge will deliver his charge to the jury on Tuesday.

Since it began March 5, the trial has heard from 62 witnesses and seen 190 exhibits. The case against Rafferty is a circumstantial one, with the key witness, McClintic, offering jurors two different stories of what happened to Tori.

From the time she confessed on May 19, 2009, until January of this year, she maintained Rafferty was the one who killed Tori by repeatedly striking her in the head with a hammer.

But a few days before Rafferty's pre-trial, McClintic suddenly changed her story, testifying that the sight of Rafferty sexually assaulting Tori prompted a surge of pent-up rage from her own childhood traumas, causing her to grab the hammer and kill the girl.

McClintic is serving a life sentence after pleading guilty two years ago to first degree murder.