"It's either you hesitating to try to get the courage up to cut her throat or you're trying to get her to do what you want her to do or it's just plain out torture," Hamby said. "It's one of the three, and I don't know which one it is, and that's why I want to know."
Brunn insisted that he wasn't responsible for those injuries.
"What's done is done," he said. "I already went to court. But I don't know how that happened."
At times, he professed to be confused by his actions. He said he didn't know why he singled out Rivera, though he acknowledged watching her at the bus stop and being attracted to Hispanic girls. On the other hand, he sometimes had a clearer recollection, such as his insistence that he didn't have sex with the child, although he said he initially planned to do so.
Interviewing a suspect, or even a convicted killer, can be a mental game, and officers are not sure whether the person is bragging or lying.
"They don't want to tell you, but their ego sometimes overrides that. They want to say something that lets you know they're extremely clever," said Ingram, the retired GBI agent. "They don't want to get themselves in trouble but they want to get credit for what they've done."
Associated Press writer Kate Brumback in Canton contributed to this report.
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