JUDY WOODRUFF: Now: a rare look at life under the rule of the Nigerian militant group Boko Haram, as filmed by the group itself.

Audie Cornish of NPR's "All Things Considered" recorded this conversation for us last week.

AUDIE CORNISH: Last year, Voice of America News Service, which is funded by the U.S. government, received a stunning trove of videos from Nigeria, 18 hours of footage recorded by Boko Haram's own cameras in 2014. The pictures comes from northeastern Nigeria.

Now, at the time, Boko Haram had total control of the region. The videos take us behind Boko Haram's assault on the Nigerian military and into villages where their leaders administer rough justice.

VOA has produced a series of four reports based on the videos.

And joining me to talk about what we can learn from these images is VOA's Ibrahim Ahmed. He hosts a weekly program for their service broadcast in Nigeria.

Thank you for joining us.

IBRAHIM AHMED, Voice of America: It's my pleasure.

AUDIE CORNISH: Now, tell us a little bit about how you were able to verify these videos.

IBRAHIM AHMED: When the Voice of America got these videos, first of all, we sat down and went through almost all of them.

And we were able to determine that they came from not Northeastern Nigeria because the people in the videos speak in Kanuri, which is the predominant language there, and which is also the language of most of the Boko Haram leadership and the members.

That was the first thing. Then there are references to Boko Haram and to events that only Boko Haram will know, like the attacks carried in some areas of Northeastern Nigeria.

AUDIE CORNISH: Your reporting shows a couple of things, one, the faces of some leaders and participates in Boko Haram, which I understand is very uncommon. It also shows how they are able to basically bring whole villages into their ideology using violence.

And in one clip, there is a tribunal where they exert their justice. How do these tribunals work?

IBRAHIM AHMED: Well, in order to control the people, when Boko Haram captures a place and they want to bring people in line, they will hold these kind of tribunals. And they will force everybody from the village or the town to attend the tribunals.

They will bring people they're accusing, whether they are drug users or drug sellers, according to them. They will bring them to these tribunals, and they will read out a statement that you are guilty of this or guilty of that. Do you accept your guilt? Well, if you accept it, fine. You just go and lay down and get killed.

AUDIE CORNISH: They do something similar with young boys and men who they conscript into fighting.

You have a video that is unusual, in that it shows a Boko Haram leader basically getting everyone to gear up to fight. Let's watch that.

NARRATOR: Awaz says the best of the martyrs are those that fight in the front. They are the ones who do not turn back until they are killed.

IBRAHIM AHMED: When Boko Haram started in 2009, initially, their membership were made up of the original followers of the (INAUDIBLE) Boko Haram. But when they started capturing territory, they started conscripting people.

AUDIE CORNISH: There is video of a failed attack, essentially, on an army barracks. And you see fighters looking for weapons. You see fighters not necessarily able to use the weapons they have.

What are the fighting capabilities of Boko Haram at this point?

IBRAHIM AHMED: Initially, Boko Haram was kind of going into fights with the military with much more powerful weapons then what the military had.

The military had AK-47 rifles, while the militants come with heavy machine guns, anti-aircraft guns. So, the military had to run away at the time. But, in 2015, the present government in Nigeria, when they started taking the fight to Boko Haram, they were able to adapt themselves and to get those kind of weapons that Boko Haram was using on them.

And that is when they started winning the war and kicking Boko Haram out of these major cities and towns.

AUDIE CORNISH: Do you feel as though these are areas that can rebuild?

IBRAHIM AHMED: It is possible, but it's going to be really difficult, because the crisis or the carnage that Boko Haram has done in the area is just unbelievable.

AUDIE CORNISH: Ibrahim Ahmed of Voice of America, thank you so much for speaking with us.

IBRAHIM AHMED: Thank you so much. My pleasure.