iirc The father was a manager, per one of the articles. I'm glad you brought this up.
I was researching a bit about turkey consumption in the USA. 29% of all US turkeys are consumed between T-giving and Christmas representing a whopping 68 million birds. Minnesota is the #1 turkey growing state at 42 million birds, followed by NCarolina 32.5 million, and Arkansas 26.5 million. The USA produces a total of 242.5 million birds per year, and a large amount is for export.
My guess is that the Jennie-O plant is in seasonal crunch mode every year from Labor Day to early December to get all that holiday turkey processed and delivered. Shift work, weekend work and OT may be expected of employees, and the plant may operate 24/7 for 2-3 months annually.
3 thoughts: 1. If the parents work excessive hours in the Fall, that might add to why an only child is with a caretaker, 2. There would be a lot of trucking activity year-round but more so in the Fall bringing turkeys from Minnesota and then taking finished product out to distribution centers, 3. Perhaps not an employee of Jennie-O but someone associated with the industry like a trucker might know the parents are working more hours, might think the father was at the plant that night
JMO