(CNN) The grandparents and uncle of a 12-year-old boy in Montana have been charged in connection with his death after police say they found evidence of them torturing the child.

Videos found by police show a pattern of abuse that included forced exercises and physical abuse, according to court documents.

James Alex Hurley had been living with his grandparents, James Sasser Jr. and Patricia Batts, for the last two years. Also in the home were the couple's children, including their 14-year-old son, who was James' uncle. The uncle is being charged as a minor.

Detectives found video from about two years ago in which James "appeared to be a healthy and well fed boy," court documents said. At the time of his death, detectives said James "appeared to be emaciated," according to the documents.

"I believe the systematic torture and beatings are perpetrated on the victim in this case that led to his death," Bjorn Boyer, deputy county attorney with the Gallatin County Attorney's Office, said during the relatives' initial appearance in court to have bail set.

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