A statement from the TBI says 34-year-old Joshua Clay Pyles of Monticello, Kentucky, was arrested early Friday on two charges of first-degree murder. Police say he killed 58-year-old Dan Dowdy and 22-year-old Cody Dowdy late Wednesday at the Sugar Shack, which is located in Pickett County along the Tennessee-Kentucky state line.
The statement says investigators quickly developed information that led them to Pyles, but it doesn't go into detail.
Police are still investigating the motive for the killings.
Pyles was being held in the Pickett County jail without bond on Friday. It wasn't immediately clear whether he has an attorney.
Pickett County Sheriff Dana Dowdy told media outlets he is related to the victims, who will be missed by the community.
"They were really loved by the community here. It's really devastated the family. They've asked me to ask everybody to keep them in their prayers," he said.
The TBI said the investigation has been assisted by two police agencies in Kentucky as well as the Tennessee Highway Patrol.
Officials say it is the first murder charges to be filed in Pickett County in over a decade.
According to the 2010 census, Pickett County had the smallest population in the state.