Photo: Reporter/producer Evan Williams

Boko Haram, an Islamist militant group, gained international notoriety when it kidnapped nearly 300 schoolgirls from a village in northern Nigeria last May, but it has been carrying out a campaign of bombings and executions in Nigeria for more than five years.

Reporter/producer Evan Williams set out to investigate atrocities committed by Boko Haram, but along the way he uncovered a very different story. Video footage given to Williams by numerous sources appeared to show state-sponsored militias — and in some cases the Nigerian military — conducting brutal interrogations and even executions of civilians suspected to be Boko Haram members.

Williams talked to FRONTLINE about how he and his team found the story, how they verified the footage, and how they tracked down witnesses to corroborate the evidence.

How did you first hear about this story?

In about May last year, we first heard of a video that allegedly showed Boko Haram training children to be suicide bombers, and that’s why we started the investigation. We sent a journalist, who we’d made contact with in Nigeria, to go into the north of the country where Boko Haram is most active to try and obtain that video. That was going to be the basis of an investigation into a story that was loosely going to be about children caught up between both sides — children caught in the war. It sounded like it was very powerful material. He spent about a week in the northeast and obtained the first eight to 10 videos.

It did not contain video of Boko Haram training children as suicide bombers. Instead, it showed militia and military conducting operations against Boko Haram. The initial clips consisted of militia and military going on what they call “security sweeps” through towns and villages in the northeast, detaining suspects who were in the videos seen as unarmed civilians, beating them up, and treating people very roughly.

We translated all those clips to try and work out what was going on. It became apparent once you translated them that they were all being accused of being Boko Haram suspects. Most of the detainees were denying that charge and saying they were innocent, but their treatment was brutal. People were being beaten up. People were being lynched. I think, initially, we had one execution at the hands of the military.

We then commissioned three journalist sources in different parts of Nigeria to reach out into their networks and try and find as much of this video material as we possibly could — doing it in a very independent way.

We collected, in the process, maybe 10 or 15 videos of Boko Haram’s absolute atrocities, including beheadings, attacks on police stations, attacks on convoys, tirades by their leader. So, we weren’t just looking to prove a point against the military. We were basically hoovering up all the video material that was out there.

And what’s really interesting about this thing is that we found out these videos were being filmed on mobile phones owned by militia members — civilian militia members working with the military — and the military themselves. This is very first-hand material that is being filmed by the people involved.

What was the point of filming these videos if they could be used to implicate them?

They told us two things when we asked that same question: Why were they filming? They filmed them as trophy videos, because they consider themselves to be in a campaign against Boko Haram. So, this is a trophy that says, “I’ve caught a guy, and this is me beating him up, and this is being tough.”

So as trophies and also what they called evidence of their interrogations. When they beat people up, they effectively beat them up to get a confession that they’re Boko Haram, and they’re videoing those things to show people in the military, their colleagues or other militia members, that “Here you go, we’ve got these guys,” right?

And they shared them. They were exchanging these videos in a very social media way. So that’s how they got out there.

Can you talk about the process you went through to verify and authenticate the video clips?

Over the course of the next six months or so we had three different sources sending us this material, all independent of each other. So each journalist source did not know that the other one was actually sending us material. There was no cross-fertilization at any point. These were coming independently, which was an important crosscheck for us that we weren’t being fed something.

When we started collecting in the early part of this year, some 100, 120 videos came in over the course of several weeks. We translated all of those videos with an independent translator in the U.K. to get an initial reading on what was going on, to build a picture on what was happening and why.

We then started to go through a verification process, which began with the transcripts. If there was no mention of Boko Haram or security, we put them to one side and noted that while they may be interesting and may show militia activities it could well have been that they were beating up a thief or a rapist or something.

We needed material that was absolutely about the campaign against Boko Haram. That was our first level.

We then started talking quite regularly to Amnesty International, which had been investigating these issues for the past few years and had issued several reports about the increasing violence by state-sponsored militia and also collecting videos and photographs themselves. We were then cross-checking with them what we had.

Through the process of translation, we were able to rule out one or two videos that had been presented online on YouTube and other places as offenses by the Nigerian forces. We could prove they weren’t. It was either the wrong language, or the wrong uniform, or the wrong location. So we discarded them.

We started with a core element of films that we knew were about Boko Haram, that were in the right area, that had come from the militia themselves — and that was important to us. We got basic information from the militia members and witnesses and from the journalist sources we were working through to give us a rough idea of where we think these things occurred and when.

The next layer then was, “Yes, we’ve got this core material,” then we went out to Nigeria. Working through the three journalist sources, we went to find witnesses or militia members who were actually there at the moment that those videos were taken.

Where possible, we’ve got two sources on everything, and then possibly more sometimes. We would then cross-check those with any known or reported incidents that concurred with those events — for example, a militia-military raid on a town called Bama — what we were being told about those activities, etc.

Simultaneously, we were running all the videos by video analysts in Britain. They looked at certain things like topography, the weather, buildings, vegetation at that time of year, all these sorts of things. We had them analyze the content of the material so that we knew that they were in northern Nigeria and not somewhere else, as much as we could tell. Each piece doesn’t definitively say it, but it builds up a story.

We also looked at the metadata — the burnt-in time and date in those clips — because they were taken with phones. That can be useful but it all depends on if they’ve set their clock to the right time. Sometimes that worked, and in one or two videos it became very important.

We also showed the videos to a forensic pathologist in Britain, because it involves a large number of people who appear to have been killed. We had him look at the nature of injuries. For example, there’s a shot of people who witnesses told us were shot by the military at close range after the Giwa prison breakout. Now, certain members of the Nigerian military have at times said, “Oh, Boko Haram blew up a bunch of explosives and killed many people.” But having a forensic pathologist, an expert, look at them — his report was that you can tell that these have all been people who’ve been shot at close range, you can see the spent cartridges. They’re not bomb victims. They’ve all been left to basically bleed to death.

Similarly, when we had him look at the bodies that we were told were taken from the Giwa barracks to the city morgue — they were bodies that showed very emaciated people, semi-naked — which also concurred with witness statements that said they were packed in so tightly that their clothes used to rot after so long. And they didn’t have gunshot wounds, most of them. Many of them, we couldn’t see gunshot wounds. They were not victims of a Boko Haram attack; they had died from something else. So that helped substantiate the claims that they were being brought en masse from the Giwa barracks in a military convoy and being dumped at the morgue.

And of course we built that up with several eyewitness statements, and local human rights investigators who’ve told us, and local journalists who’ve told us this was happening last year. We pieced it together really using those sources.

Did you run into any videos that were fake or not what they purported to be?

Not many, but there were a few. There were two in particular. One was a long line of men on the ground who had been beaten severely by uniformed and armed men. When we first saw it, it had been portrayed to us as a Nigerian military crackdown in the northeast. When we saw it, we were horrified. We thought, “Wow, this is very important,” but right at the very end, you can’t really hear what’s going on, but our translator, who was Nigerian from the north, said there’s a word in French. We looked again at the uniforms and the uniforms were not Nigerian. He looked at the buildings and said these don’t look like Nigerian buildings. We pulled that one out, because it looked like it was in an ex-French colony somewhere.

There’s another one of people being burned to death — burned alive on a roadside. Initially, we were told these were detainees who were being killed by the local people, by the militia. But actually we found that was a video that was already out there on YouTube, and that it was apparently alleged witches being burned in Central African Republic.

So we went through very carefully and took out anything that first of all we found a problem with in our processes, second of all, that we weren’t sure of, or third, that we couldn’t substantiate either via an eyewitness or the transcript or the militia information. The most important thing is we based it around people who could give us first-hand information about what you see in the clip, not what they think was happening generally.

The basis of our filming trip in Nigeria was interviewing people who were there. The way we verified that was, we didn’t show them the clip to start with in the interview. We had people working for us reaching out all over the northeast to say, “We believe there was an incident at around this time. Were you there? Do you remember what happened?” We described it that way. They came in. We interviewed them about what happened. Then, we showed them the clip.

In the film you see a few of these former militia members talking. What made them come forward, and were they afraid of retaliation?

Yeah, they are, which is why they’re anonymous. It’s a very unpredictable and violent place, so we took a lot of efforts. First of all, anybody that we met, we did not go to their hometowns. Partly for their own safety and also so that we could operate. Because it’s so sensitive, a foreign crew is just very unlikely to be able to operate over a sustained period of time like we needed to do, which was to dig very deeply. So, we based ourselves in a neighboring place that was several hours from where these people live.

There were two or three people that we commissioned to help us who were from the town. They were our people up there, and we coordinated with them. They went and got the people in what they thought was the appropriate way. They would then bring them down to us. We had maybe four, five or six trips of people coming down to see us. And we paid their costs for bus fare and food. But that road is dangerous, and a lot of people took great risks coming to see us, but it was still a lot better than us turning up at their homes. Somebody tips off the military, or somebody pieces this back together and says, “Those white guys were here and they visited this woman.” We really didn’t want that to happen, so we took a lot of effort to make sure they had that distance.

When it came to the militia guys, one militia guy who was contacted by a local journalist who lives in the north was very proud — is very proud of the work that they’re doing. We have to acknowledge that in the early days they did have some success in arresting some Boko Haram people.

These militia guys see themselves as valiant defenders of their communities against a very savage insurgency. So they don’t see all what they’re doing as wrong. They don’t see the problem with beating a confession out of somebody, because in their minds that’s how you do it. They don’t see the problem that if you’re not guilty, you’re going to say you’re guilty just to stop the beating. They don’t see a problem with treating somebody harshly if they think you’re Boko Haram.

So this one guy, Mohammed, who came down to us, and was very, very proud of the work they were doing, came to explain to us what they were doing and how they were saving their communities. That was his motivation. And the couple of clips he gave us were to indicate that, you know, they were dealing very harshly with these suspects, and that’s how you gotta do it. Even though he was quite happy to do it, he wanted to be anonymous because people just don’t know if things are going to turn. You never really know — who’s going to be in power, or you may annoy somebody. So they’re very, very cautious. And it reinforces a very important thing: Everybody is scared of Boko Haram, but everybody is terrified of the military. And this is the military that’s meant to be protecting them.

So they were all anonymized because of their fear of the Nigerian army.

The second [militia] guy came down because he really changed his mind about the violence.

Is this the one whose friend was targeted?

Abdul, yes. He started off joining because he thought they were doing the right thing, they were going to defend their communities, they’re all brave guys, etc, etc.

But what happened with him was, first of all, he filmed an event where a young boy was beaten very savagely, and he says eventually died. He didn’t understand why the military did that. Well, he told me that the military did it because the guy kept refusing to admit that he was Boko Haram. So they kept beating him so he would confess, and in the end, you know, they killed him. His terminology about that was, “You wouldn’t be able to stand it up there because it was so violent.”

“We all became monsters,” was his phrase. So he’s got one step of evaluating that things had gone badly.

He was then assigned to offload bodies from military vehicles at the morgue. And then he saw his friend’s body. They’d grown up as kids together, basically from babies, he said. And when he saw his body, he was like, “He’s not Boko Haram. Who accused him of being Boko Haram? Why did the military kill him? Why did this happen?” And that’s when he realized that things had gone too far.

The issue for them all is, he then disappeared for a couple of days because he was so upset, and the military started asking questions about him. They’re sort of trapped. So if you’re not in the machine, you can be seen to be suspicious. They’ve got to be very, very careful about how they operate, and what they do and see.

That’s why he came down to give us a very frank appraisal that he thought the violence had really gone too far.

Did you, at any point during filming, come across members of the Nigerian military, or militias, besides the people you interviewed?

No, we operated in an area really where the militia themselves are less active, and we avoided the Nigerian military. The main reason for that was that we were conducting sensitive interviews with eyewitnesses, human rights workers. We had material on us, they were bringing us material, and we had our network of people as well, so we avoided contact with [the military]. If they know that you’re up to something that they’re not particularly happy with, you won’t know it but you’ll be on their radar, and it would have been very dangerous for the people we were meeting. We deliberately avoided contact with the Nigerian military and security forces.

Who were the locals most afraid of?

I would say they’re afraid of Boko Haram, and they’ve been afraid of the Nigerian military in equal measure. They’ve been equally afraid of both.

One of the reasons the militia formed was to try and side with the army, to save themselves getting arrested. They’re like, “No, no, no, we’re with you guys.” But many civilians are equally afraid of the Nigerian military, because lots of people get arrested.

Now, these militias, do they have any organizational structure, or did they just spring up?

They sprang up out of young men in the communities who were, first of all, fed up with Boko Haram in their towns; second of all, who were trying to stop the mass arrests of themselves by the military, when the military moved into town and escalated its operations about two years ago.

It was very irregular to start with. They would form these militias and go to the military and say: “Don’t arrest us. We know these guys. We’ll go and get them for you.” The military would say, “Well, great, that sounds like a plan.”

But then, around May last year they were more formalized by the military into what was called the CJTF, the Civilian Joint Task Force.

Some of them were trained by members of the military, some of them got paid. And we even got some video of an army colonel telling them to try and behave nicely, to not go around burning people’s homes. There was definitely a connection. They are state-sponsored. They went on joint operations with the military, and their main purpose was to detain people and hand them over. They’re an irregular force that was subsumed into an official contact with the army, but not recruited or formed into a military force. They’re still used a civilian force and given the power to detain, and also given the power to beat confessions out of people.

As I watched the film, I wondered whether the backlash from the military and militia’s crackdown has led to more people joining Boko Haram. Have you heard anything about that at all?

Yeah, a school teacher from Bama told us that because of military and CJTF actions in towns which led to the deaths of large numbers of young men, he thought it could happen to them at any time. His exact words were: “The next village would then side with Boko Haram because they don’t want to be killed by the military and the militia when they come into town.”

Now, I’ve heard different accounts of this because Boko Haram is a really extreme and savage and deadly organization. I’ve also heard that people don’t want to join Boko Haram necessarily, but the actions of the military force them away from the government. So what they would do is not inform, or not have contact with the army and the militia. Try and avoid giving information, just trying to survive between these two forces.

So, I think it does lead to support for Boko Haram, but it doesn’t lead to a mass recruitment drive. Joining Boko Haram is a very serious action, so it might mean that a village might be sympathetic to Boko Haram if they can somehow defend them against these military abuses. But it’s a very grey area.

It’s more like a policy of acquiescence to their actions, or soft support, or not going to the government.

For many people in the United States, Boko Haram first became a headline-grabbing name when the girls were kidnapped in Chibok. Was there any sense among your contacts that the international attention increased the pressure on the military or led to more severe crackdowns?

The kidnapping of the Chibok girls certainly led to more aggressive military actions in the northeast in certain towns, which in itself sparked a more savage response by Boko Haram. So, actually, it’s escalated. There have been accounts and reports of military columns going into a town, and of massacres. And then reprisal attacks by Boko Haram, and then reprisal attacks by the military. There was more pressure on the government to be seen to be doing something definitive against Boko Haram, and that led to more savage actions by the military. The level of military action is pretty high already, so I would say it increased, but hard to quantify how much.

I think if anything, probably, the international attention underlined problems within the Nigerian military in dealing with Boko Haram. There was more attention on them as to 1) Why can’t they go rescue the girls? 2) Why did this happen in the first place? 3) Were they actually listening to intelligence that was given to them? 4) How they operate on a normal basis in these areas, 5) How there are all these mutinies against their officers because of corruption.

All this disgruntled nature about the way it’s being conducted became more apparent with that extra pressure. All of this combined is why they’re so brutal when they go into an area. They’re afraid. They don’t have any information. They think everybody’s Boko Haram. One thing leads to another, which then engenders more anger against the military and more support for Boko Haram.

And just to clarify, the militias were primarily Muslim?

Yeah, they’re all Muslim.