In what he described as a case with "a complex set of circumstances," Missoula County Sheriff T.J. McDermott said Tuesday that Caressa Jill Hardy, 51, is being held on suspected deliberate homicide related to the 2013 deaths of two different people.
The victims' identities are not being released at this time, McDermott said. "This is a very difficult time for the families of these victims," he said.
The sheriff said he doesn't believe there are any other suspects in the case.
Hardy was arrested Monday and is being held in the Missoula County Detention Center.
The case was reported to law enforcement in 2016 and has been under investigation for more than a year by the sheriff's office, the Missoula Police Department and the FBI.
"Many details cannot be released pending completion of our investigation," he said.
McDermott anticipated that formal charges will be filed against Hardy on Wednesday, when Hardy also is to appear in Missoula County Justice Court.
Sheriff's Detective Capt. David Conway said that the case initially was reported to a law enforcement agency outside Missoula, but wouldn't say where.
Watch missoulian.com for updates.