here to those chilling new detail office that American soldier, Bowe bergdahl's captivity. You'll remember when that video was released, bergdahl blinking in the sunlight in that trick waiting for... See More
here to those chilling new detail office that American soldier, Bowe bergdahl's captivity. You'll remember when that video was released, bergdahl blinking in the sunlight in that trick waiting for U.S. Special forces to arrive. Many wondering at the time if the blinking was the result of years of captivity, perhaps being held in the dark. Tonight here, ABC's chief foreign affairs correspondent Martha Raddatz on what she's learned about bergdahl's attempted escape from the Taliban and what they put him in afterward. Reporter: It was after he tried to flee his Taliban captors he was put in a metal cage in the dark for weeks at a time, bergdahl has told staff helping his recovery, according to a senior U.S. Official. An official saying it is no surprise that the Taliban would beat and abuse the soldier. And "The New York times" is reporting he has asked not to be called sergeant, saying he didn't earn it. He was a private when he disappeared, but he was promoted on schedule, which always happens when a soldier is taken captive. And while he is recovering physically, walking, talking, his mental health remains an issue. A senior official says the 28-year-old solider is still not prepared for a reunion with his family and he has no idea the firestorm his release has created. Just over a week ago, Bowe bergdahl's parents were celebrating his freedom. Tonight, they are facing threats against their lives. The threats so serious, the FBI has been called in. One saying, "I'd be ashamed to say he is from your town, needs to be shot and his dad right along with him. Taliban lovers." It's a backlash fueled in part by the results of an army investigation done at the time of bergdahl's disappearance, released this week. It backs up what his fellow soldiers have already said, that bergdahl walked away from his base willingly. He was not forcefully taken off the base. He left on his own accord. Reporter: The Obama administration has fiercely defended the deal that freed bergdahl, but another investigation is being launched. When bergdahl finally does come home, he will not go directly to his hometown of Halley, Idaho. He will go to brook army medical center in Texas to continue his recovery. David? Martha Raddatz with us tonight. Martha, thank you.
This transcript has been automatically generated and may not be 100% accurate.