Tupelo, Miss. - Federal agents of all sorts invaded northeast Mississippi several days ago, on a mission: Find the man who sent a poison-laced letter to the president. But the United States government quickly found itself entangled, once again, in a misunderstood land dominated by squabbling tribes and petty vengeances.

Agents first arrested an Elvis Presley impersonator, released him, and then on Saturday arrested his nemesis, a karate instructor. Gradually investigators concluded that what they had descended upon was probably less about the president - or the U.S. senator and retired state judge who also received letters - than a serious case of indigenous bickering.

That shocks no one here. "Tupelo is a kaleidoscope," said sociologist Mark Franks, who grew up in nearby Booneville. There are true geniuses walking the streets of Tupelo, he said, and incredibly wealthy, generous people. But also, "every wall-eyed uncle and 'yard cousin' - just referencing the local pejorative - makes it into Tupelo, Miss. It creates a peculiar culture."

Tupelo is best known as the hometown of Presley, after whom it has named streets, waterways and dry cleaners.

Unlike many other Southern towns its size, it has several excellent museums, street art and a public arena large enough to attract the Ringling Bros. and Barnum & Bailey Circus this month. That's when someone shot Carol, a circus elephant, in what seems to be the first elephantine drive-by ever. Carol is recovering, but Tupelo Police Capt. Rusty Haynes said his investigation has stalled "because, to be honest, there are a lot of possible perpetrators."

So people in the area were not surprised when the FBI, Secret Service and other agencies showed up looking for whoever sent letters laced with ricin to President Obama, Sen. Roger Wicker, R-Miss., and retired Mississippi Judge Sadie Holland.

The agents quickly nabbed a man in nearby Corinth named Paul Kevin Curtis. He worked as an Elvis impersonator, spun wild conspiracies about the local hospital selling body parts and apparently signed the poisoned letters with his own initials.

But the FBI found no evidence of ricin in Curtis' home and no incriminating research on his computer. They decided he hadn't sent the letters after all and released him Tuesday. Within hours agents had raided the home of his archenemy: J. Everett Dutschke, karate instructor.

Curtis claimed Dutschke wanted to frame him. It wouldn't be the first skirmish between Tupelo's most famous son and a karate man. In 1973, several men climbed on stage during a concert by Presley. The singer felt threatened and fought the men, alongside his bodyguards. He felt sure the men had been sent by estranged wife Priscilla's new boyfriend, his own nemesis: Mike Stone, karate instructor.

Curtis, 45, and Dutschke, 41, have intertwined for years, feuding over small-town grievances as labyrinthine and intricate as any global conspiracy. They met in 2005, and were friendly for a time. When he wasn't teaching karate, Dutschke worked for Curtis' brother Jack at an insurance office. Both men knew Wicker, and both had connections to the 80-year-old Holland.

It's unclear at what moment the hostilities began, but a few years ago Curtis, who worked at the local hospital, developed a theory that doctors were harvesting organs to sell on the black market. He wrote a book about it called "Missing Pieces." Dutschke published a local newsletter at the time, and after some negotiations apparently rejected Curtis' writings.

There was the question, too, of who had the bigger intellect. Dutschke was a member of Mensa, the club for people with high IQs. A few years ago, Curtis posted a fake Mensa certificate on his Facebook page, which sent Dutschke into a rage. "I threatened to sue him for fraud for posting a Mensa certificate that is a lie," Dutschke told Tupelo's newspaper, the Daily Journal. "That certificate is a lie."

"Aw, yeah. I don't know why Kevin did that," Curtis' father, Jack, said recently in Cleveland, Miss. "These boys were just after each other."

Both men have made multiple trips to jail. Curtis was arrested for, among other things, assaulting a Tupelo lawyer - for which he received a six-month sentence from Holland. In January, Tupelo authorities charged Dutschke with molesting children. He pleaded not guilty, but he shut down his karate school, called Tupelo Taekwondo Plus, while awaiting trial.

After the FBI released Curtis, the two enemies' paths diverged. Curtis headed for New York. "Can you believe that?" Jack Curtis said. "Now he's got publishers all trying to jump the gun on each other to publish his book first. Isn't that something?"

On Saturday the U.S. attorney charged Dutschke with "knowingly developing, producing" and stockpiling ricin. If convicted he faces maximum penalties of life imprisonment and a $250,000 fine.

Hours before his arrest, Dutschke answered his door by opening it just enough to look out with one dark eye. He held a kitten, which also looked outside. "I'm sorry, I just...," he started. His voice was soft. "I can't talk. I'm so, so sorry."

Could he say, at least, what started this mess?

"Just look around you," he said. "This place is crazy."