Jan. 14, 2012— -- The mayor of a small Montana town where a teacher vanished and has been declared dead appears to blame an influx of oil workers for the crime.
Sherry Arnold, 43, has not been seen since she went running early Jan. 7 and the only clue she left behind was a single running shoe next to the road in her hometown of Sidney.
Arnold's school district has announced that they were informed of her death, but it is not clear whether authorities have recovered a body.
The FBI have taken a 47-year-old man into custody and are questioning a 22-year-old man 330 miles away in Rapid City, S.D. But neither has been identified or charged in Arnold's disappearance and death.
Investigators are trying to determine whether Arnold, the mother of six, was abducted and killed.
The town of about 5,000 people has seen an increase in violence due to an influx of oil field workers in recent months because of the Bakken oil boom in North Dakota
Sidney Mayor Bret Smelser spoke darkly of oil workers since Arnold was determined to have died.
"We own the day," Smelser said. "They own the night. Unfortunately, Sherry was running in the early hours of the morning."
Arnold was a teacher in Sidney since 1993, teaching at both the middle school and high school, where she was a math teacher at the time of her death.
"Sherry is one of those teachers that every parent wants in front of their child," Sidney School District Superintendent Daniel Farr told ABCNews.com.
"She is caring, first and foremost, one that is there before and after school helping students," Farr said. "She gets to know her students. She becomes a mentor to many a student that goes on to become a math teacher."