When 4-year-old Andrew Burd arrived at a hospital in critical condition in the fall of 2006, doctors didn't have a clue as to what was wrong with him. Blood tests soon revealed that he had salt poisoning, or hypernatremia. Andrew's levels were off the charts -- almost double the norm and among the highest ever recorded.
Doctors turned to Hannah Overton, a 29-year-old pregnant mother of four who was in the process of adopting Andrew. She told them Andrew had thrown a fit that afternoon after he'd been fed a full lunch. Instead of giving him more food, she said she put a few dashes of creole seasoning in a sippy cup of water.
But that didn't calm him, she said, and a few moments later he fell to the floor, vomited and complained of being cold. Overton said she suspected the flu, but after an hour and a half, Andrew's condition didn't improve. That's when she and her husband, Larry, took Andrew to the hospital.
The Overtons' story aroused the suspicions of doctors and investigators. The next day Andrew died and the devout Christian couple, which had no criminal history, became murder suspects. As the investigation continued, authorities developed a theory that Andrew's death was an intentional poisoning.
"We were just waiting for someone to look at it and say 'This is just an accident,'" Larry Overton told "20/20." "Instead, we were arrested."
To investigators, Andrew's sudden and bizarre death was no accident. Within days, the authorities had begun weaving a sinister tale of murder. They painted Hannah Overton as a pregnant mother of four young children who became overwhelmed with the arrival of a foster child.
The arrest warrants painted the Overton home as a house of horrors, where Andrew was monitored by a camera and was punished with spicy seasoning. Detectives even used the Overtons' children to build a case against them, saying unusual forms of punishment had been previously used.
"This case boils down to a woman who, basically, tortured a child," said prosecutor Sandra Eastwood, "becoming so enraged she forced him to have 23 teaspoons of hot pepper and then watching him die in agony."
A grand jury returned an indictment on capital murder. In the state of Texas, if a child younger than 6 dies at the hands of another person, it's considered a capital case. The charge carries a minimum life sentence.
The Overtons' church community saw the accusations against Hannah and Larry as ludicrous and rallied around the couple, raising nearly $700,000 for their defense.
"What they came up with and what really happened were completely different things," said the Rev. Rod Carver.
"It's so bizarre," Noreen Carver, Rod Carver's wife, said, "because [Hannah Overton's] really the last person you would think would be charged with this type of crime."
The Overtons and their supporters claimed there was a rush to judgment -- that the authorities had never considered alternate theories. The Overtons said that in the four months Andrew had lived with them, he had exhibited excessive tantrums and obsessive eating.