A 15-year-old boy has been charged with first-degree murder in connection with the death of Teresa Robinson, an 11-year-old girl whose body was found last May in the remote Garden Hill First Nation in northern Manitoba.

"I knew this would come someday, but didn't know it would feel like this — it really hurts," Teresa's mother Sandra Robinson said. "I didn't think someone that young would do that."

The Garden Hill First Nation is a fly-in community on the edge of Island Lake, about 475 kilometres northeast of Winnipeg.

"As a parent and as a mom, I can only imagine how incredibly difficult the past 10 months have been for this family," Supt. Paulette Freill said just after 1 p.m. CT Friday at a news conference in Winnipeg.

RAW: RCMP Supt. Paulette Freill speaks on the Teresa Robinson homicide arrest1:15

"Teresa's murder was an absolutely senseless and horrific crime. It shook the community of Garden Hill."

The boy, who is from the community, was arrested on Thursday and the charges were laid on Friday. He cannot be named under provisions of the Youth Criminal Justice Act.

'They're all shocked'

Garden Hill First Nation Chief Dino Fleet said the arrest has caused mixed reactions in the community.

"They're all shocked. We have been expecting this, or wanting to close this case, looking for answers," he said.

Teresa Robinson

A 15-year-old boy has been arrested and charged in the death of 11-year-old Teresa Robinson. (Facebook)

"There was fear in the community.… We had no idea what was going on, if this person was still out there. There's a big relief at the same time in the community for people that have little children. For the parents, for the grandparents."

Teresa had last been reported alive leaving a birthday party in the community around 9 p.m. on May 5. Her body was found in a wooded area on May 11.

"All I keep thinking was, 'It's someone from here.' I tried to think who," Sandra Robinson said. "I told my daughter before, 'Don't trust nobody, we don't know where this person is and we don't know who he is.'"

The condition of Teresa's remains first led people to believe she had been killed by a wild animal. Her death was later determined to be a homicide.

Last month, RCMP took the unusual step of asking all males in the community age 15 to 66 to give DNA samples as part of the investigation.

"The scope of the collection is something that was new in Manitoba. It had the full support of the community and leadership," Staff Sgt. Jared Hall said.

"Our investigators have spent tens of thousands of hours on this case and not a single day has passed where it hasn't been worked on, thought of … toiled over."

Hall said no amount of training can prepare officers to deliver information to a family about the death of an 11-year-old girl.

"It takes an emotional toll on our members," he said. "I can't explain what it's like to deliver news like this to a family member.

RAW: RCMP Staff Sgt. Jared Hall talks about the toll the investigation took on Teresa's family, officers and the community1:01

"If I was a family member — I'm a parent, heaven forbid something like this happen to me — I just want to know what happened," he said, adding police "ask them for their trust and faith."

Hall would not confirm whether the 15-year-old provided DNA to investigators, adding that all samples have now been destroyed.

Beginning the healing process

'We have to remember that when you're that young that you're not responsible for your action.' - Sheila North Wilson

Hundreds of people volunteered their time and efforts to find Robinson and help with the subsequent investigation.

"The tragedy of Teresa's death will never, ever be forgotten and there will always be a deep sense of loss for the family and in that community," Freill said.

"It's our hope however that the charge of first-degree murder laid today can begin the healing process and help bring some closure to the family."

Roughly 600 tasks were carried out by about 80 officers as part of the investigation, including 400 interviews with people in the community, RCMP said.

Fleet said that while the community heals it will also reflect on whether anything could have been done to prevent Teresa's death.

"These are the things we have to go back and look at … the social problems in our communities," Fleet said. "We have to look at every step, every angle."

'This speaks to a larger issue'

​Sheila North Wilson, grand chief of Manitoba Keewatinowi Okimakanak, which represents the province's northern First Nations, said she hopes the arrest will bring some closure to the family and the community in Garden Hill.

It's important to keep the age of the suspect in mind throughout the healing process, North Wilson said, and the role society plays in influencing the kind of behaviour that led to Teresa's death.

"We have to remember that when you're that young that you're not responsible for your action, you are acting out on things you think and see and you feel," North Wilson said.

"It's unfortunate that it's turned out this way for him, but he is a young man and we have to support the family in their healing process as well, because they are going through a tremendous time right now.… This speaks to a larger issue in all of our communities across the north — especially in MKO territory — that our young people are in crisis, they are in despair. They need hope, they need opportunities, they need resources and I think it is upon all of us to make sure they get what they need to find happiness and success in their lives."

Teresa was the youngest of six children.

"She always said, 'I'm going to be the baby forever and ever, so we told her, 'Yes you will,'" Sandra Robinson said. "She would have a big smile on her face."

RCMP said the investigation is continuing.

CBC in Garden Hill: 15-year-old boy charged with 1st-degree murder in death of Teresa Robinson0:43