A Woodstock, Ont., police officer broke down on the stand Thursday when describing the moment he learned Tori Stafford was dead.

Det. Const. Sean Kelly was an investigator on the Stafford case when the eight-year-old girl was abducted on April 8, 2009 from her school.

Her body was found several months later stuffed in garbage bags in a field north of Guelph, Ont.

Kelly said Terri-Lynne McClintic confessed to the killing May 19, 2009 and the case went from an abduction to a homicide, he said through tears.

The trial will likely adjourn Friday and resume Tuesday when McClintic will begin her testimony.

McClintic, 21, pleaded guilty to first-degree murder in the case.

Michael Rafferty, 31, is charged with first-degree murder in the brutal killing of the eight-year-old girl.

He has pleaded not guilty to charges of murder, kidnapping and sexually assaulting Stafford.

The court previously heard testimony from Woodstock police acting Insp. Paul Hess Wednesday, who said he "didn't have a very good feeling" when he learned of Stafford's disappearance.

Hess said he deployed all resources available to search for the little girl, even asking hundreds of officers from nearby towns and cities to assist.

Police received 900 tips in the first week alone and canvassed more than 2,500 homes.

Another investigator told the court more than 1,100 pieces of physical evidence and 4,500 photographs have been assembled for the case.

Mother's emotional testimony

But it was Stafford's mother, Tara McDonald, who testified in the London, Ont. courtroom Wednesday about the day her daughter went missing that helped shed more light on the case.

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

McDonald said she was once again struggling with the drug by the time her daughter went missing in 2009. 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.

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."

McDonald says she has now been clean for nearly six months.

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 Stafford walking towards that parking lot, the police officer testified.

The court also heard from Laura Perry, who said she saw McClintic and Stafford walk by as she was waiting for her two sons. Perry testified that she recognized Stafford 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.