"It's the worst thing I've ever seen," Johnson County Sheriff Mike Reece said, adding he had never seen anything like it in his 27 years in law enforcement in the area. "We've had murders, but nothing like this. This is just senseless."

He said Billy Clay Payne, Jr. and Billie Jean Hayworth were killed last month after they deleted Jenelle Potter, the daughter of one of the suspects, from their "friends" list. Both were shot in the head and the man had his throat cut.

The couple's 8-month-old baby was in the mother's arms, unharmed, when the bodies were found.

Marvin Enoch "Buddy" Potter Jr., 60, and Jamie Lynn Curd, 38, were each charged on Wednesday in Mountain City in northeastern Tennessee with two counts of first-degree murder. The men were arrested on Tuesday.

The case was not the first involving violence linked to Facebook. Last year in Iowa, a woman was arrested on accusations of setting fire to a friend's garage after she was defriended on the social network site, local media reported.

In Texas, a man was accused of hitting his wife after she failed to "like" a Facebook post he wrote about the anniversary of his mother's death, according to media reports.

In the Tennessee case, Reece said a couple of harassment cases had been filed against Jenelle Potter in court over "someone blocking her or taking her off."

"Once you've crossed her, you've crossed her father too," Reece said, adding that Jenelle Potter, in her late 20s or early 30s, stays home with her parents and was constantly on Facebook.

Her father, "Buddy" Potter, will return to court next week for a bond hearing after he hires an attorney. Curd, also a second cousin of one of the victims, was appointed an attorney and bond was set at $750,000 for each murder count. His preliminary hearing will be in March.

No charges have been filed against Jenelle Potter, the sheriff said. She could not reached for comment.

Curd's attorney, R.O. Smith, an assistant public defender, said it was "safe to say there's more to it than the Facebook problem, it appears."

"I wish I could provide more of what went on, but there's needless to say a lot of rumors swirling around and nothing substantiated on the rumors," Smith said.

(Reporting By Tim Ghianni; Editing by Mary Wisniewski and Cynthia Johnston)

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