JUDY WOODRUFF: For more on all of this and a look at some of the options before the military in the Bergdahl matter, we turn to New York Times reporter Eric Schmitt.

And retired Lieutenant General Dana Chipman. He was the Army's judge advocate general and, as such, was the Army's top lawyer. And we welcome you both.

Eric Schmitt, to you first.What is the best information you have about the circumstances of Bergdahl leaving his post?

ERIC SCHMITT, The New York Times: Right now, Judy, the circumstances appear to be, as the soldiers in his unit have suggested, that he did voluntarily walk off his base in June of 2009 into a hostile environment with the Taliban nearby in Paktika province.

Why he did that is exactly — is still not known. And that's what's going to be going on with these debriefings that you mentioned in your report. Clearly, this was an individual who had expressed mixed concerns about his mission in Afghanistan to his parents in e-mails and to his soldier comrades. So, exactly why he did what he did when he did it, those are still answers we're waiting for.

JUDY WOODRUFF: And, Eric, this is not just one of his comrades. This is several who are saying he walked away.

ERIC SCHMITT: That's right, and that's what Pentagon and other military officials have told us here at The New York Times as well, that he did voluntarily walk away from his post in Eastern Afghanistan in 2009.

But, again, what his intentions were, there have been some suggestions that he deliberately deserted to join the Taliban. We have seen no evidence yet of that. But, again, as both General Dempsey and Army Secretary John McHugh said today, there will be a full investigation once his medical and reintegration are complete.

JUDY WOODRUFF: So, General Chipman, let's talk about an investigation. As we heard from Eric Schmitt and other reports we have seen, there are not just one, but there are several soldiers who served with Mr. Bergdahl who say that he left of his own accord. Is that the same as desertion?

LT. GEN. DANA CHIPMAN (RET.), Former Judge Advocate General, U.S. Army: Well, no, it doesn't — it doesn't mean the same as desertion.

He may have left of his own accord. That will be proven in the final investigation, because what we have right now is an effort that went under way when he left back in 2009. And now we will have a chance to interview Sergeant Bergdahl to determine from him what was your intent, what was your perspective, what were you thinking at the time, and that will enable us to conclude that investigation that really needs his perspective as well.

JUDY WOODRUFF: Well, as we, I think, said in that report, we said the Pentagon concluded in 2010, the year after he left, that he did walk away. So what more information would they need? If he did make this decision on his own, what would be a mitigating circumstance that would explain it?

LT. GEN. DANA CHIPMAN: Well, you will want to know from him, what was your motivation, what were the circumstances that led you to walk away, if that's, in fact, what occurred?

And I don't think you can determine that without getting into his state of mind and the actions he took at that time, and only he can fully supplement what we already know. And so I think, you know, one of the elements under the code, under the Uniform Code of Military Justice to prove desertion is an attempt to remain away permanently from military duty.

That's what we will find out. What was his motivation, what was he thinking, what did he intend to accomplish at that time?

JUDY WOODRUFF: So was — so there's an investigation which goes on for presumably months? Is that what normal procedures would be?

LT. GEN. DANA CHIPMAN: It can be quicker than that, but I would expect, with a case of this notoriety, with a case of this interest, that it will be a thorough investigation that could take a matter of months. And at that — the conclusion of that investigation, there will be a decision, was there criminality involved, will we in fact press charges under the Uniform Code?

JUDY WOODRUFF: Eric Schmitt, what are Bergdahl's comrades who are in the Army serving with him at the same time, what are they saying about what they believe was on his mind at the time?

ERIC SCHMITT: Well, they are saying is that he expressed disillusionment with the mission in Afghanistan. Remember, this is 2009. The Taliban are resurgent now in Eastern Afghanistan in particular. They're in this very remote outpost, just 30 or so soldiers, and it's a very small outpost in the mountains of Eastern Afghanistan, not far from the Pakistan border.

Of course, the surge of troops into Afghanistan under the new president, President Obama at that time, had not yet started. So it was a very difficult time and, as the soldiers in your report indicate, hostilities all around. So it must have been a very dangerous and depressing environment for these soldiers.

JUDY WOODRUFF: And — but what they are saying and what you were telling us is that he gave every indication after a period of time that he was disillusioned and that he was thinking about leaving the military. We know there were communications between him and his parents.

ERIC SCHMITT: That's right, but as the general said, to really understand his long-term goal, was he just in a fit of depression and walked off the base? What were his goals, what were his intentions, what were his long-term goals?

Again, there has been no indication from military investigators that we have spoken to both during this whole period that he's been missing and more recently that he had any intent to go over to the other side to help and abet the Taliban. Again, these are things we don't know until the military investigators actually speak to him and find out what was his state of mind at the time, what was going through his head and what were his intentions when he left that post.

JUDY WOODRUFF: And, General Chipman, just to be a little bit more clear about what we're talking about here, so you said they will be wanting to know what his intention was, his long-term intention. Does that mean that he had to have been planning to join the enemy or simply that he was walking away from the United States military?

LT. GEN. DANA CHIPMAN: It doesn't mean that he was planning to join the enemy, Judy.

Desertion is when you leave military service with an intent to remain away permanently from military control. So what your ultimate motivation is, to join the enemy, to go away to Canada, to Europe, desertion is complete when you have proven — or when we have proven, the prosecution has proven that you do not ever intend to return to military control.

And we have had desertion as an offense under the code for a long time, prosecuted many deserters in Vietnam and other conflicts.

JUDY WOODRUFF: And how tough is it to prove?

I know that General Martin Dempsey, who is the chairman of Joint Chiefs, he was quoted today as saying he is innocent until proven guilty, as is the case with all Americans. But what — how tough a standard is it to prove that someone deserted?

LT. GEN. DANA CHIPMAN: I think it's very difficult to prove, in this sense. It's a subjective standard.

You have to be in the mind of the soldier. And how do you show that intent? It can be circumstantial, in the testimony of his peers, fellow soldiers. It can be his direct quotes, "I intended to leave and never come back to the U.S." But it can be very difficult to prove a desertion case, unlike simple absence without leave, where, if you leave without authority, that's pretty much all you have to prove.

JUDY WOODRUFF: So, does the Army go into a case like this with some predisposition one way or another or with a completely open mind?

LT. GEN. DANA CHIPMAN: Judy, with a completely open mind.

In fact, as General Dempsey said, if we prefer charges here, he is in fact presumed innocent until proven guilty beyond a reasonable doubt in a court-martial proceeding. And so we will have no predisposition. We will have a charge sheet and we will let that criminal prosecution play out, as we do in any other case.

JUDY WOODRUFF: General Dana Chipman, we thank you.

Eric Schmitt, we thank you both.

ERIC SCHMITT: Thank you.

LT. GEN. DANA CHIPMAN: Thank you.