A husband accused of dismembering his wife confessed in grisly detail to killing her at the family’s Michigan home while the children were in the house, police said Monday.

“He gave a very lengthy confession,” Macomb County Sheriff Mark Hackel said at a press conference.

Stephen Grant admitted murdering his wife, Tara Lynn Grant, after police found a Ziploc bag in the woods containing human blood, latex gloves, plastic bags and metal shavings. It was the final piece of evidence authorities needed for probable cause to search the Grants' house, in which they found a human torso, Prosecutor Eric Smith said.

The metal shavings linked the bag's contents to Stephen Grant, who worked at a tool-and-die shop, the prosecutor said.

"He's presumed innocent at this time," Smith said. An arraignment was expected on Tuesday.

After examining the body parts, the medical examiner said the cause of death was strangulation. DNA tests were to be conducted to confirm the identity of the remains.

"The examination showed bruising externally visible on her neck," County Medical Examiner Daniel Spitz said, adding that there were some blunt force injuries on the head and face area that are indicative of a struggle.

Stephen Grant wanted to "clear his mind" by confessing, Hackel said. He "did indicate the method in which he caused her death," after which he took the body to a creek to dispose of the remains. Hackel said he would not discuss the motive.

Hackel said there was no indication the children were aware what was happening in their house during their 34-year-old mother's death. "We've had lengthy conversations with the au pair," he said.

The children, a girl, 6, and a boy, 4, were staying with relatives. In a statement released through the hospital, Stephen Grant said he loved them and "looks forward to seeing them again as soon as possible."

Stephen Grant had been recovering from hypothermia at Northern Michigan Hospital after his capture and was transferred to the Macomb County Jail Monday afternoon. A mental evaluation also was scheduled to ensure he receives proper care, Hackel said.

"The effects of the hypothermia have essentially resolved, and the frostbite in his extremities has improved rapidly as well," Dr. John Bednar, the hospital's medical chief of staff, said during a news conference. It could take weeks to determine whether there will be long-term effects from the frostbite, even though it's a minor case, he added.

Bednar declined comment on Grant's mental state, saying only that he was "awake, alert, calm and cooperative."

Officers discovered a female torso Friday in the garage of the family's home 30 miles north of Detroit. Police found more body parts at a nearby park; the remains were believed to be those of Tara Grant.

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Stephen Grant, 37, fled in a friend's pickup truck after police obtained the search warrant. Police traced calls from his cell phone to Wilderness State Park, at the tip of Michigan's Lower Peninsula, where they found him cowering under a fallen tree. He was dressed in a shirt, socks and pants in the 14-degree weather.

"I don't think he probably could have made it much longer in those kind of conditions," Emmet County Sheriff Pete Wallin told reporters.

Tara Grant last was seen Feb. 9. Her husband reported her missing five days later. Police say the day she disappeared, the couple had argued over her frequent business trips abroad.

Hackel said it didn't appear Stephen Grant tried to kill himself, although his former attorney, David Griem, had described him as suicidal. Griem said Sunday he would no longer represent him because of irreconcilable differences.

Stephen Grant was taken into custody around 6:30 a.m. Sunday after an all-night search, offering no resistance. He was silent as he was hoisted into the helicopter, Loeb said.

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The Associated Press contributed to this report.