Marvin Potter, left, one of two men charged with first-degree murder in the deaths of Billy Payne Jr. and Billie Jean Hayworth. Lee Talbert/Johnson City Press/AP Photo; Tennessee Deputy Attorney General''s Office

A Tennessee couple removed a woman they knew from their list of friends on Facebook, and authorities say the woman's father and her boyfriend, upset over her treatment, retaliated last week by murdering the couple in their home.

Marvin Potter, 60, and Jamie Curd, 38, have each been charged with two counts of first-degree murder and are being held in the Johnson County Jail, said authorities in Mountain City, Tenn.

On the morning of Jan. 31, the Tennessee Bureau of Investigation alleged, the two men shot and killed Billy Payne Jr. and Billie Jean Hayworth in the house they shared. Payne's throat was slashed.

The couple had an 8-month-old baby boy, who was found unharmed in his mother's arms.

Payne and Hayworth had filed a legal complaint last year about Jenelle Potter, 30, Marvin's daughter, accusing her of making threats against them by phone and online, police said. The killings happened, police added, after the couple "defriended" Jenelle on Facebook.

"That's basically what sparked it," said Johnson County Sheriff Mike Reece. "Her life is spent at that computer. She's had some health problems, and she wasn't working.

"It's just a senseless thing," said Reece. "She'd been blocked on Facebook by Billy Jean. Once you cross her, it's a big thing to her father, too. And he's something to deal with."

Reece said Jenelle Potter had had online run-ins with other people in the area.

"There was bad blood between the two families," said Assistant Deputy Attorney General Matthew Roark. "Altercations, verbal at least, in the grocery store, things like that had been reported."

Authorities did not pursue the complaint made by Payne and Hayworth, he said, because it was hard to prove. At the time, Tennessee law did not make cyber bullying an offense separate from telephone threats.

Marvin Potter has not yet retained a lawyer, police said, and is being held for now on $200,000 bond.

Curd's bail was raised to $1.5 million after he retained a public defender and had a preliminary hearing. No charges have been filed against Jenelle Potter.

Payne was 36 and Hayworth was 23, said police. Payne was found in his bedroom, and Hayworth was found in the baby's room.

"It is the saddest case I've ever seen," said Roark. "The sheriff said it was the most senseless crime he'd ever handled."