Fifteen-year-old Katie Hamlin's nude and partially burned body was found on July 2, 2002, along the famous Cherokee Trail of Tears in Georgia's Appalachian Mountains.
For two-and-a-half years, the murder went unsolved, and police became desperate for a break in the case.
Roberto Rocha, a 20-year-old landscaper and the son of a minister, became a suspect in the crime. Rocha was a schoolmate of Hamlin's, and it seemed he had some kind of relationship with the young girl -- his number was found in her cell phone's speed dial.
Rocha went to the police voluntarily to be questioned. After all, he had an airtight alibi: He's been out of the country, in Brazil, the day Hamlin was killed.
Going Along With the Story
During the questioning, police accused Rocha of killing Hamlin, which he vehemently denied -- at first. But a rare look inside the interrogation room shows how suspects can become confused, frightened and disoriented, and sometimes confess to things they didn't do.
"I didn't kill nobody, man. What are you talking about?" Rocha said during the police interrogation.
The police sometimes stretch the truth about evidence, which happened in this case. "I got three witnesses saw your truck," a cop told Rocha, who said he would submit to a lie detector test.
The police changed tactics and began to threaten Rocha.
"You better start telling the truth, or I'm going to lock your damn ass up!" said a policeman. "You don't know what we know. You think we just picked you out of the blue? Now start telling the truth!"
Rocha had never been arrested, and according to his attorney, Brian Steel, he also has a low IQ, which made him particularly vulnerable to suggestion. "The child is 20 years old with a 12-year-old's mind," said Steel.
The police continued to challenge Rocha, acting as if his presence at the crime scene was fact. After more than two hours, Rocha said he became confused and exhausted. He and his attorney said that police told Rocha if he went along with them, he could go home.
"Roberto Rocha just cracked and said, fine, I'll tell you what you want to know," said Steel.
But from the start, Rocha had trouble with key details of the case, such as where Hamlin's body was found. But the police "helped" him with that. One officer drew a map and said: "There's the bridge. You were there. ... Here's where you were parked."
"OK, I parked there," Rocha said on the videotape.
Steven Drizin, an attorney who specializes in false confessions, watched Rocha's interrogation.
"Drawing the map is like the cardinal sin of interrogation," Drizin said. "If you feed him those details, there's no way to know whether or not he's simply agreeing with what you're saying or he was there and he knows those facts."
Drizin said that Rocha was unable to provide the most basic details of the case, and when he did, he made mistakes. Rocha told police it was chilly outside, even though it was July, and he said it was hard to see because there were so many trees, when in fact, there were no trees in the area.
"He's trying to come up with the story. He's making this stuff up as he goes," Drizin said.
Capt. Ron Hunton, who questioned Rocha that night, said an interrogation is an emotional battlefield.
"You get caught up in it. You get so wrapped up in it because it's intense," Hunton said. "You know murder's a rough business. You can't go in there and say, 'Did you do it? No, I didn't do it. OK, thanks for coming in.' You can't do that."
But there are risks in going too far with an interrogation. Rocha had been questioned the whole time without a lawyer, and over time, he began going along with what his lawyer called a completely false confession.
"Every single thing that had anything to do with that homicide, that information was first supplied by law enforcement officers and then repeated by Roberto Rocha," said Steel.
"Roberto Rocha was trying to do anything he could to leave that interrogation room and to appease the officers."
But rather than getting out of police custody, Rocha was arrested and charged with the murder of Katie Hamlin.
But what about that alibi -- that he was in Brazil at the time of the murder?
The Rev. Joao Rocha, Roberto's father, provided all kinds of documentation to prove that: stamped passports, plane tickets, pictures, witnesses from the trip and even an X-ray of Roberto's mouth from a visit to a Brazilian dentist on July 2, 2002 -- the day of the murder.
"It was the best alibi that I could ever imagine a person having," Steel said.
But once Rocha confessed, police were slow to accept any other explanation. Hunton said that the proof Rocha was out of the country was "equivocal."
"Yeah, he's on the flight manifest. His name is on here. But they couldn't tell me for sure, 100 percent certainty, yeah, this guy was on the plane," said Hunton, the interrogating officer.
Hunton also said the Department of Homeland Security should have a record of Roberto's green card being recorded at the airport in 2002, but they did not.
In the end, the same tape that had nearly hung Rocha would help set him free. Hunton re-examined Rocha's confession tape and noticed a number of inconsistencies.
Finally, after 15 months, all charges against Roberto Rocha were dropped. Jamerson Mangrum, a friend of Hamlin's and the last person seen with her, was convicted of her rape and murder this past December.
"You can't take a confession and just lock the guy up and throw away the key and let a jury decide his guilt or innocence. I'm not willing to take that chance," Hunton said.
Too often, though, questionable confessions are not re-examined, said Drizin, the attorney who specializes in false confessions.
"That's an instinct that should be valued and respected. ... That's extremely rare."