Her cries for help would keep him awake at night, an injured little girl pleading for food and water in an unheated basement filled with garbage and cobwebs.
But it was the sound of silence that triggered a 12-year-old boy to make a horrible discovery in his own home.
The youngest stepbrother of Phoenix Sinclair told a Winnipeg jury Thursday how he found the five-year-old girl's body moments after she got what would be her final beating at the hands of her mother and stepfather.
The boy, now 15, fought back tears as he described Phoenix's final moments alive in June 2005.
"I went downstairs and there was no answer from her. I just touched her back and it was all cold. Her eyes were open. I put my hand on her mouth... she wasn't even breathing," he said.
His father, Karl McKay, and stepmother, Samantha Kematch, had been "taking turns" beating Phoenix, he said, and then left the Fisher River First Nation home to visit a relative.
"They were passing her back and forth, punching her," said the boy.
After finding Phoenix's body, he called his grandfather looking for help. McKay and Kematch returned to the home, picked Phoenix up and placed her in a bathtub filled with warm water.
"They weren't even crying or anything," the boy said. "I'd look at their faces. I saw no tears, nothing. They didn't even care what they were doing."
The couple finished washing her body, then wrapped her up in a tarp, took it outside and placed it in the trunk of their vehicle, he said.
"They said 'watch your baby sister, we're going to go to the dump and bury her,' " he said.
That was the last time he saw Phoenix. He said McKay and Kematch told him not say a word about it.
"They told me that if anybody asks, just say Phoenix went to Winnipeg to live with her dad," he said.
Her death would go unnoticed for nearly 10 months until the boy and his older brother told their mother what they'd witnessed. Police found Phoenix's remains buried near the dump.
McKay and Kematch are now on trial for first-degree murder.
McKay's son told jurors earlier today how he watched helplessly as the couple repeatedly abused Phoenix "just for the hell of it." He said she was often forced to sleep in the "dark, cold" basement without any food or water.
"It was dirty down there, you could see spider webs and garbage everywhere," he said.
He awoke sometimes at night to the sound of Phoenix "sobbing through the vents." He would often go down to give her water and even tried to bring her a heater one night, only to be caught by his father and threatened.
"She was just curled up in a little ball," he said. "The only time Samantha and Wes would go downstairs was to hit her."
He told jurors about beatings, including when McKay broke a metal broomstick over Phoenix's back and then used the broken end to cut her knuckles.
"There was blood all over. It got infected," he said.
McKay would also stomp on her and choke her to the point of unconsciousness, he said.
"Her eyes would go back, her body would go limp and he'd just let her drop," he said. "He'd hit her so much that she wouldn't even cry anymore. She'd just take it."