At a news conference Saturday afternoon, police said Mitchell's husband was arrested on Friday night.
Police said they are preparing to lay second-degree murder charges against him in connection with Mitchell's death. The man, whose name has not been released, is also expected to be charged with indignity to a body.
Mitchell, 31, was last seen at her home in the southeast community of Ogden on Oct. 29, 2012. Her family reported her missing to Turner Valley RCMP on Nov. 12 of that year and told police it was very unlike her to not contact her family for such a length of time.
On Jan. 9, 2013, RCMP turned the case over to the Calgary Police Service.
Police executed a search warrant Friday night at Mitchell's Ogden home and say they found what are believed to be human remains.
Police say it's not clear why Mitchell's children and visitors did not notice a decaying body in the home in the two years since her disappearance.
According to investigators, police had been called to the couple's Ogden home for a domestic complaint before Mitchell disappeared but no charges were ever laid.
Mitchell's family has been notified of the discovery. Police say her children, ages five and seven, are safe.
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