The Flathead County Sheriff’s Office and Montana Department of Justice are looking for information on a Kalispell woman missing since Valentine’s Day.

At about 7 a.m. that day, a Thursday, 31-year-old Nicole Waller left Fairview to return to Kalispell and her children, a teenage daughter and two young sons. But she never showed up here.

Waller was reported missing two days later, and by the following Monday, her maroon 1999 Ford Expedition was found abandoned on the side of U.S. 2 outside Poplar.

“Mothers traditionally don’t abandon their children,” Agent Mark Hilyard of the state’s Division of Criminal Investigation said. “This is clearly not normal behavior and has every indication of a homicide.”

A release from the state Justice Department stated that while law enforcement officials will not release details of the investigation, “a number of factors point to foul play.”

“Someone witnessed suspicious activity taking place,” Hilyard said. “It also appeared odd that her children’s pet guinea pigs were still in the vehicle when it was recovered.”

Wednesday’s statement from the state Justice Department was the first time Waller’s family had been explicitly told by law enforcement that she is now believed to be dead.

“It’s a lot to take in, we’re pretty much crushed,” said Carmen Keibler, Waller’s sister. “You hope that your family member’s going to come home and going to be safe, and that’s not what happened, obviously, in this case. We’re just crushed, devastated.”

She said the finality of the statement was the difficult part, as family members had known all along that it was a possibility.

“It’s always in the back of your mind because it’s been nine months,” Keibler said. “You kind of at some point have to face the fact that something horrible has happened, and today has confirmed it.”

Despite the unfortunate nature of the family’s contact with law enforcement, Keibler said the contact has been good and that the different agencies have treated the family well and kept them in the loop regarding the investigation.

“They’ve been very patient when we’ve called and vented about ‘Why haven’t we heard anything?’” she said, later adding, “They’ve been very kind.”

Keibler also thanked the Flathead Valley community for its support, particularly that shown through a “Find Nicole Waller” Facebook page through which people kept their eyes and ears open and shared statuses in an attempt to spread the word and help bring Waller home.

For now, though, the family is just trying to cope with the new development. “It’s a lot to take in,” Keibler said.

The case continues as they still look for closure and try to find out what exactly happened to Waller.

“There’s someone out there who knows the truth,” Hilyard said.

He encouraged members of the public to provide any assistance they could, since a single observation someone may consider unimportant often can break a case open.

Anyone with information about Waller’s disappearance may anonymously contact Hilyard at (406) 791-2709 or call the Sheriff’s Office at (406) 758-5600.

Along with the state justice department and the local sheriff’s office, the Sidney Police Department, Richland County Sheriff’s Office, Roosevelt County Sheriff’s Office and Federal Bureau of Investigation have at some point been involved in the investigation.