WINNIPEG - As five-year-old Phoenix Sinclair suffered a final, deadly beating on the concrete basement floor of her family's home, a terrified stepbrother peeked around the corner and witnessed the assault, an inquiry into the girl's death heard Monday.

"I was just a little kid, you know, didn't even know what ... was going on," testified the stepbrother, who is now a 20-year-old man and cannot be identified under a publication ban.

Phoenix's mother, Samantha Kematch, was sitting on the stairs and watched her new boyfriend, Karl McKay, punch and kick Phoenix for 15 to 20 minutes on that day in June 2005, the stepbrother said. Afterward, the couple left and he, then a boy of 12, went to check on the battered girl.

"She was all cold. I put my hand by her mouth. She wasn't even breathing."

Later, McKay and Kematch came back and tried to revive the girl.

"They brought her upstairs, put her in a bathtub, tried running water on her, tried to do CPR."

The inquiry is examining how Manitoba child welfare failed to protect Phoenix, who had spent much of her life in foster care or with family friends before being returned to Kematch. Months before Phoenix's death, social workers paid a short visit to Kematch, didn't actually see the child, but decided all was well.

The beating that killed Phoenix was not out of the ordinary. The stepbrother and another sibling witnessed Phoenix being abused, neglected, starved, shot with a BB gun and forced to eat her own vomit. Other children in the home were not physically abused.

Kematch and McKay buried Phoenix in a shallow grave near a landfill and told others she was still alive. They continued to collect welfare benefits with her listed as a dependent.

Eight months later, one of the child's stepbrothers told his mother — a former common-law spouse of McKay — and she called authorities. Kematch and McKay were arrested a short time later and were convicted in 2008 of first-degree murder.

McKay's former partner, whose identity is also protected under a publication ban, told the inquiry Monday that McKay had always been a violent man and had tried to kill her twice in the five years they were together.

"He always fought me where the bruises wouldn't show. It was always under my clothes."

On one occasion, she testified, McKay tried to throw her and their infant son down a staircase. Another time, he came at her with a machete.

"(McKay's) sister gave me a machete because I was alone all the time, and he tried to use that machete on me."

McKay also had a long record of domestic violence outlined in the province's family services central database. But social workers never caught on that he had become part of Phoenix's life.

The inquiry has already heard of a list of failures by social workers.

Social workers were sometimes unaware of who was taking care of Phoenix — usually it was friends of the family or relatives, for days or weeks at a time. In 2003, she was seized from her biological father's home after a day-long drinking party where suspected gang members were present.

The father was told to undergo alcohol counselling before he could get his daughter back. He didn't, but regained custody anyway.

The step-brother's mother who testified Monday lashed out at social workers at one point for their handling of Phoenix's case.

"Social workers failed her."

Earlier on HuffPost:

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  • Rodney Stafford, father of slain Victoria Stafford, speaks to the media as he arrives at the courthouse in London Ontario, Tuesday, May 15, 2012 for the sentencing hearing for Michael Rafferty, who was convicted Friday of Victoria's murder. THE CANADIAN PRESS/ Geoff Robins

  • After The Verdict

    Rodney Stafford, father of slain Victoria Stafford reacts after Michael Rafferty was found guilty on all three charges at the murder trial in London, Ontario, Friday, May 11, 2012. <br> THE CANADIAN PRESS/Dave Chidley

  • Reaction

    Rodney Stafford, father of slain Victoria Stafford holds a photo of his daughter as he speaks to the media, with his mother Doreen Graichen, sister Rebecca Nichols and brother Rob Stafford looking on, after Michael Rafferty was found guilty on all three charges at the murder trial in London, Ontario, Friday, May 11, 2012. <br> CREDIT: CP

  • Longest Day

    Rodney Stafford, father of Victoria (Tori) Stafford, holds his head in in hands late in the afternoon at the courthouse for the Michael Rafferty murder trial in London, Ont., Friday, May 11, 2012. <br> CREDIT: CP

  • Rodney Stafford, father of slain eight-year-old Woodstock girl Victoria Stafford, talks to reporters during a break in proceedings at the trial of Michael Rafferty, the accused in his daughter's murder in London, Ontario, Tuesday, May 1, 2012.THE CANADIAN PRESS/ Geoff Robins

  • The grave of Victoria (Tori) Stafford on Easter Sunday, the third anniversary of the day the eight-year-old girl vanished while walking home from school, in Woodstock, Ontario, Sunday, April, 8, 2012. (THE CANADIAN PRESS/Dave Chidley)

  • Dirk Derstein, defence lawyer for Michael Rafferty, the accused in the murder of Woodstock, Ontario schoolgirl Victoria Stafford talks briefly with reporters during a break in proceedings at the trial in London, Ontario, Tuesday, May 1, 2012. THE CANADIAN PRESS/ Geoff Robins

  • Terri-Lynn McClintic and Michael Rafferty are shown in these police handout photos released as court exhibits at Rafferty's trial in London, Ont., Wednesday, April 4, 2012. THE CANADIAN PRESS/HO

  • Michael Rafferty and Terri-Lynne McClintic embrace in this still image taken from a police handout video dated May 8, 2009. Rafferty visited McClintic twice at a detention centre, where she was taken after being arrested days after the killing of Victoria Stafford on an unrelated matter. (THE CANADIAN PRESS/HO)

  • Terri-Lynn McClintic is shown in police handout photos released as court exhibits at Michael Rafferty's trial in London, Ont., Thursday, April 5, 2012. THE CANADIAN PRESS/HO

  • Michael Rafferty is shown in a police handout photo released as court exhibits at Rafferty's trial in London, Ont., Thursday, April 5, 2012. THE CANADIAN PRESS/HO

  • Michael Rafferty's 2003 Honda Civic is shown in this court handout photo along with other exhibits. A tiny spot of dried blood on the rubber moulding of the back passenger side door on Michael Rafferty's car was found to contain DNA matching the eight-year-old girl's profile, forensic biologist Jennifer McLean testified Wednesday at Rafferty's trial. THE CANADIAN PRESS/HO

  • A butterfly earring worn by Victoria Stafford are shown in this evidence photo released Tuesday, April 3, 2012 at the trial trial of Michael Rafferty. Court has heard that she had borrowed the earrings from her mom on April 8, 2009. THE CANADIAN PRESS/HO

  • Victoria Stafford's T-shirt is shown in this evidence photo released Tuesday, April 3, 2012 at the trial trial of Michael Rafferty. THE CANADIAN PRESS/HO

  • Michael Rafferty is transported from the courthouse in the back of police cruiser in London, Ontario, Wednesday, March, 14, 2012. Rafferty is facing charges in the death of Victoria (Tori) Stafford. Court is hearing that Rafferty was "stressed out" in the days after her disappearance.(THE CANADIAN PRESS/Dave Chidley)

  • Accused Michael Rafferty is shown in court in London, Ont., Monday, March 5, 2012 in this artist's sketch. The trial of Rafferty, 31, began Monday nearly three years after Victoria Stafford disappeared outside her elementary school in Woodstock, Ont. (THE CANADIAN PRESS/Tammy Hoy)

  • Terri-Lynne McClintic, left, is transported from court for proceedings in the Michael Rafferty murder trial in London, Ontario, Friday, March, 16, 2012. Rafferty is charged with several offences including first-degree murder in the death of eight-year-old Victoria "Tori" Stafford. McClintic is already serving a life sentence after pleading guilty two years ago to first-degree murder in Tori's death. THE CANADIAN PRESS/Dave Chidley

  • Evidence letter written by Terri-Lynne McClintic in the Michael Rafferty murder trial in London, Ont., Thursday, March, 22, 2012. Rafferty has pleaded not guilty to first-degree murder, sexual assault causing bodily harm and kidnapping. McClintic has already plead guilty of first degree murder in the case. (THE CANADIAN PRESS/Dave Chidley)

  • Rodney Stafford, father of slain Victoria (Tori) Stafford walks from the courthouse during a break in the proceedings for the Michael Rafferty murder trial in London, Ontario, Thursday, March, 22, 2012. Rafferty has pleaded not guilty to first-degree murder, sexual assault causing bodily harm and kidnapping. THE CANADIAN PRESS/Dave Chidley

  • A tearful Tara McDonald, mother of slain eight-year-old Woodstock girl Victoria Stafford, receives a hug from partner James Goris during a break in proceedings at the trial for Michael Rafferty, the accused in her daughter's murder in London Ontario,Tuesday, March 13, 2012. THE CANADIAN PRESS/ Geoff Robins

  • Tara McDonald (center) mother of slain Victoria (Tori) Stafford walks from court after completing her testimony in the Michael Rafferty murder trial in London, Ontario, Wednesday, March, 7, 2012. (THE CANADIAN PRESS/Dave Chidley)

  • Terri-Lynne McClintic is transported from court for proceedings in the Michael Rafferty murder trial in London, Ontario, Friday, March, 16, 2012. (THE CANADIAN PRESS/Dave Chidley)

  • Terri-Lynne McClintic is transported from court for proceedings in the Michael Rafferty murder trial in London, Ontario, Friday, March, 16, 2012. (THE CANADIAN PRESS/Dave Chidley)

  • Terri-Lynne McClintic testifies at the Michael Rafferty murder trial in London, Ont., Tuesday, March 13, 2012. (THE CANADIAN PRESS/Tammy Hoy)

  • The Disappearance And Death Of Tori Stafford

    Victoria (Tori) Stafford, 8, disappeared while on her way home from school in Woodstock, Ont., on April 8, 2009. (Photo: An undated family handout, CP). <em>The following text is by the Huffington Post Canada, will files from CP</em>

  • For weeks, her parents, family friends and community members searched for the little girl. <em>(Photo: Cassandra Craig and Shiloh Roth hang a poster for missing Stafford, 8, on a street corner in Woodstock, Ont., on Friday April 10, 2009. THE CANADIAN PRESS/Dave Chidley)</em>

  • Meanwhile, hundreds of police searched local ponds, a landfill, and used a helicopter for aerial sweeps of Oxford County. <em>(Photo: Ontario Provincial Police officers search the Oxford County landfill site Tuesday, April 21, 2009, for clues. THE CANADIAN PRESS/Dave Chidley)</em>

  • Tori's mother, Tara McDonald, held daily press conferences as the national media descended on the town of 35,000 in southern Ontario. <em>(Photo: Tara McDonald speaks to reporters in Woodstock, Tuesday, April 21, 2009. THE CANADIAN PRESS/Dave Chidley)</em>

  • The girl's body was found three months later in a field near Mount Forest, Ont. <em>(PHOTO: Funeral home attendants load the remains of the girl into a hearse July 20, 2009. THE CANADIAN PRESS/Darren Calabrese)</em>

  • Michael Rafferty, 31, is charged with first-degree murder, sexual assault causing bodily harm and kidnapping in the death of Victoria Stafford. His trial began with jury selection in the last days of February, 2012. <em>(Photo: Rafferty leaves the courthouse in Woodstock, Ont., Feb. 7, 2011).</em>

  • Terri-Lynne McClintic, now 21, has already been convicted of first-degree murder in the girl's death. She pleaded guilty in April 2010 and was given a mandatory life sentence, with no chance of parole for 25 years. <em>(PHOTO: An undated Facebook photo of McClintic).</em>

  • McClintic's guilty plea could not be reported until December 2010 due to a sweeping publication ban imposed by Justice Dougald McDermid. The ban was partially lifed by the Supreme Court of Canada, though some details remain under the ban in order to protect Rafferty's right to a fair trial. <em>(PHOTO: Justice McDermid enters court in Woodstock, Ont., on Friday, April 30, 2010. THE CANADIAN PRESS/Geoff Robins)</em>

  • After Tori's funeral, her father, Rodney Stafford, went on a bike ride to Edmonton in her memory with Child Find Ontario, the <a href="http://www.thestar.com/news/ontario/article/1135756--the-main-players-in-the-tori-stafford-murder-case-where-are-they-now?bn=1" target="_hplink">Toronto Star reports</a>. He raised more than $25,000. He plans to attend the <a href="http://www.cbc.ca/news/canada/toronto/story/2012/02/26/stafford-murder-trial.html" target="_hplink">murder trial, telling CBC,</a> "There'll never be closure because I still wake up every morning without my daughter." <em>(PHOTO: Stafford, father of slain eight-year-old Tori Stafford, leaves court in London, Ont., on Monday, Jan. 16, 2012. THE CANADIAN PRESS/Geoff Robins)</em>

  • Rafferty's trial was moved from Woodstock to nearby London in light of publicity surrounding the girl's death. His lawyer, Dirk Derstine, suggested outside court that people should keep an open mind. "I expect that the evidence to be called will be different than what everybody is perhaps expecting," he said. <em>(PHOTO: Dirk Derstine leaves court in London, Ont., on Monday, Jan. 16, 2012. THE CANADIAN PRESS/Geoff Robins)</em>

  • OPP Detective Inspector Bill Renton was the lead investigator in the Tori Stafford murder case. He's seen here arriving at the Middlesex Court House in London, Ont., Monday, Feb. 27, 2012 on the first day of jury selection in the first degree murder trial of Michael Rafferty. <em>(PHOTO: THE CANADIAN PRESS/Mark Spowart)</em>

  • Tori Stafford seen with her older brother, Daryn Stafford, in this family handout. <em>(Dave Chidley/Canadian Press)</em>

  • Crown lawyers outside the courthouse where the Michael Rafferty trial is being held.

  • The Trial, In Photos

    Rafferty's mother spoke Monday, May 7, for the first time since her son was arrested and charged in May 2009, six weeks after Tori was killed. She placed the blame for what happened to Tori squarely on Terri-Lynne McClintic. "My son is innocent," Deborah Murphy said as she faced a wall of cameras outside the courthouse. "This could happen to any man that's walking around right now. Terri-Lynne McClintic has wrecked our lives and I just hope that justice is served and that he's free." (THE CANADIAN PRESS/Dave Chidley)

  • Tara McDonald, mother of slain eight-year-old Woodstock girl Victoria Stafford, receives a hug following the last day of evidence in the trial of Michael Rafferty, the accused in her daughter's murder, in London Ontario, Tuesday, May 1, 2012. THE CANADIAN PRESS/ Geoff Robins