Criminal investigation opened into disappearance of Grand Forks prosecutor’s daughter

Katelyn Berry, 26, was reported missing from her Sidney, Montana, apartment on Dec. 31. Berry is the daughter of Grand Forks County Assistant State's Attorney Carmell Mattison.

Katelynn Berry, a 26-year-old resident of Sidney, Montana, was last seen here at her apartment south of town on Dec. 21 before being reported missing ten days later. Local police have opened a criminal investigation into her disappearance.
Jeremy Turley / Forum News Service
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SIDNEY, Mont. — Law enforcement officials have opened a criminal investigation into the disappearance of a 26-year-old woman from Sidney, Montana, who was reported missing on Dec. 31.

Katelynn Berry was last seen by her father, Hank Berry, in her Sidney apartment on the afternoon of Dec. 21 when he brought her lunch. He reported her missing 10 days later after she had not answered his phone calls or text messages for days.

Berry is the daughter of Grand Forks County Assistant State's Attorney Carmell Mattison. Her father, a local warehouse manager, said Berry has moved back and forth between Grand Forks and Sidney, an Oil Patch city of about 6,300 that sits 10 miles west of the North Dakota border.

26-year-old Katelynn Berry
Katelynn Berry, a 26-year-old resident of Sidney, Montana, was reported missing last month. Police have opened a criminal investigation in an effort to find the former Grand Forks resident.
Submitted Photo

Law enforcement decided to begin a criminal investigation, on top of treating her disappearance as a missing person case, because it’s “suspicious” that no one has heard from her or knows her location, and when authorities searched her apartment they found her cell phone and winter jacket — items she is not likely to leave behind, said Richland County Sheriff John Dynneson.

Police had not identified any suspects as of Monday night, Jan. 3.


In addition to searches on foot with police dogs, authorities have scanned the area around her apartment from the air via drone and helicopter, Dynneson said.

Law enforcement is also reaching out to Berry’s friends and acquaintances who might have spoken with her around the time she went missing, Dynneson said. They’re also sifting through her cell phone records, which include a text message sent from her phone on Dec. 23.

Multiple agencies, including the U.S. Border Patrol, the FBI and the Montana Division of Criminal Investigation, are assisting local law enforcement in the investigation into Berry’s disappearance, Dynneson said.

Berry’s father told Forum News Service his daughter usually stayed close to the apartment he built for her next to his workshop. She did not work a job, drive a vehicle or drink alcohol, and she has struggled with mental health issues in the past, her father said. Much of her time was spent listening to music, drawing and hanging out with friends, he noted.

“I just want her home,” Hank Berry said through tears. “I just want to give her a big, old hug.”

Authorities are urging members of the public with any information about Berry’s disappearance to contact law enforcement. Dynneson said residents who live in and around Sidney are encouraged to search their own properties for anything suspicious that could be connected to Berry’s disappearance.

If you have information relevant to Berry’s disappearance, call the Richland County (Montana) Sheriff's Office at 406-433-2919, or the Sidney Police Department at 406-433-2210.

A flyer showing a picture and biographical information about missing woman Katelynn Berry hangs on a door to the Town Pump, a truck stop in Sidney, Montana, just a few blocks from Berry's apartment.
Jeremy Turley / Forum News Service

Michelle (she/her, English speaker) is a Bismarck-based journalist for The Forum of Fargo-Moorhead and Report for America, a national service organization that places journalists in local newsrooms to report on under-covered topics and communities.
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