The mother of Tori Stafford said she crossed paths with the woman convicted of murdering the eight-year-old girl in the months before the killing occurred.

Tara McDonald outlined a difficult stretch in her life when she abused OxyContin as she testified Wednesday inside a London, Ont., courtroom during the first-degree murder trial of Michael Rafferty.

McDonald told the court she started taking OxyContin in 2005 and went to a methadone clinic in Woodstock, Ont., to clean herself up when it became a problem.

But the problem resurfaced in 2009, when her eight-year-old daughter went missing and was found dead in a field several months later. She says she has now been clean for nearly six months.

McDonald said her OxyContin use brought her in contact with Terri-Lynne McClintic. The 21-year-old woman has pleaded guilty to first-degree murder in Tori's death.

McDonald said she was once again struggling with the drug by the time her daughter went missing. McDonald said she went to McClintic's home twice, once to obtain OxyContin from the woman's mother and the second time to discuss dog breeding.

McDonald said she was discussing breeding shih tzu dogs with Carol McClintic in her dilapidated home on a futon mattress, when she saw Terri-Lynne.

"We sat on the edge and we started discussing the dogs and Terri-Lynne came in," McDonald said. "She (had left) to go and use a payphone. She gave her mom a message then sat down. She was...very, very under the influence and I'm not sure if she had even noticed we were there that day."

That initial meeting occurred either in January or February, McDonald said.

She added that, to her knowledge, neither of her children had contact with the family.

McDonald also testified during a cross-examination that her daughter never would have gone off with a stranger.

McDonald's testimony comes on the third day of a trial against Rafferty, 31, who has been accused of kidnapping, sexually assaulting and murdering the eight-year-old girl.

Stafford went missing after leaving her Woodstock school on April 8, 2009.

After an extensive search, Stafford's body was found three months later in a field north of Guelph, Ont.

Rafferty has pleaded not guilty to charges of first-degree murder, sexual assault causing bodily harm and kidnapping.

An emotional McDonald described her daughter as a girl who loved "girl things" but also loved to play with bugs and jump in puddles.

"She'd be outside in a dress picking up worms and bugs, getting dirty and jumping in puddles," she said. "She loved music and 'Hannah Montana,' art, colouring. She spent a lot of time with her brother. They were extremely close."

Earlier in the day, the court hear from an OPP forensic identification officer who said more than 1,100 pieces of evidence and thousand more photographs were collected during the exhaustive search for Tori.

OPP Const. Gary Scoyne told the courtroom that the collection was gathered and catalogued as search crews combed southern Ontario for the missing girl.

Nearly 4,500 photographs were taken over the course of the investigation and will also be entered into evidence.

Teacher first to testify

The trial began this week with the testimony of Tori's Grade 3 teacher, Jennifer Griffin-Murrell, who fought back tears as she described the child's caring, sensitive demeanor.

"She was kind of like a mother hen to a lot of the younger kids in the class. She always wanted to help," Griffin-Murrell told the court. "She had a little spunk. She was very dramatic in a way that she liked music and drama, and always liked to do little role plays or air bands. She was just a lovely little girl."

In her testimony, Griffin-Murrell said the last time she saw Tori was when the girl ran back into the school just moments after class had been dismissed for the day. Tori had returned to retrieve a pair of butterfly earrings that belonged to her mother, the teacher said.

On Tuesday, Det. Const. Robin Brocanier showed the court surveillance video of McClintic, wearing a white coat, walking with the young girl up the street from her school at 3:32 p.m. on April 8.

Brocanier said the video shows a car "of interest" with black rims travelling from the school's direction and pulling into a retirement home parking lot up the street.

The video shows McClintic and Tori walking towards that parking lot, the police officer testified.

The court also heard from Laura Perry, who said she saw McClintic and Tori walk by as she was waiting for her two sons. Perry testified that she recognized Tori but did not know McClintic, agreeing under cross-examination that they did not appear to be strangers.

Crown attorney Kevin Gowdey has said his case will also include testimony from McClintic and DNA evidence from police, which was allegedly found on Rafferty's car door.

Superior Court Justice Thomas Heeney has told the jurors the trial will likely last at least 10 weeks, though proceedings could stretch into June.