How the BBC verified that video of a grisly murder in Cameroon, step-by-step

Benjamin Strick’s Twitter mentions were blowing up.

“I am bogged down with interviews at the moment,” the web developer told Poynter in a message Tuesday, a few hours before connecting on Skype. “I have a TV crew coming in about 10 minutes. I have no idea how long it will take.”

While exhausted by the attention, Strick said it was welcome. After all, it took three months to finish the in-depth, open-source investigation that he helped produce for the BBC.

The media requests (including this one) came after the news organization’s new investigative unit, Africa Eye, published the project in a Twitter thread Monday morning, racking up nearly 70,000 likes and more than 50,000 retweets as of this posting. The thread, which summarized a video report, outlined how a team of open-source investigators verified a video from sub-Saharan Africa that had gone viral on social media.

THREAD In July 2018, a horrifying video began to circulate on social media. 2 women & 2 young children are led away by a group of soldiers. They are blindfolded, forced to the ground, and shot 22 times. #BBCAfricaEye investigated this atrocity. This is what we found… pic.twitter.com/oFEYnTLT6z — BBC News Africa (@BBCAfrica) September 24, 2018

The video depicts a group of soldiers escorting two women and two young children, all blindfolded. Then they’re forced to the ground and shot 22 times.

“We were — like everyone who saw it — appalled by the video of the killing,” said Daniel Adamson, a series producer with Africa Eye, in a message to Poynter. “We thought it was important to at least try to find out who was responsible for the killing of those women and children.”

So the BBC started looking into the video, which allegedly took place in Cameroon. In July, when the video first went viral, the government there dismissed the allegations as “fake news” on the basis that the soldiers depicted were not wearing the right gear or carrying the right weapons.

“We suspected there was enough in the video to geolocate it, so we took a close look,” Adamson said.

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Strick, a digital investigator in his free time, first became involved after the BBC reached out to him on Twitter asking for help. He said there’s a community of people on the platform who use open-source tools to verify or debunk media in their spare time.

“I do this stuff for free; I’m just a bit of a nerd,” he said. “There’s a handful of us on Twitter that just love zooming on satellite imagery, having a look at buildings and things like this. When we saw this video come out, we all jumped on it straight away.”

Along with a few other freelance investigators — many of whom contribute to Bellingcat — as well as full-time BBC journalists, Strick started looking around on Google Earth to see if he could pinpoint the location of the video. While many social media users claimed it took place in northwest Cameroon, some said it was actually in Mali.

The first thing they did was look at the background. In this case, there was a mountain range and a cluster of buildings nearby. That gave them something to go by.

After searching Google Earth, the team received a tip to look near Zelevet, a small town in the far north of Cameroon, near the border with Nigeria. Then, by using iMovie to slow down the video, they matched some of the details with those in satellite imagery from Sentinel Hub, confirming the location of the shooting.

Putting all this evidence together, we can say with certainty that the killings happened herehttps://t.co/ION682W82n pic.twitter.com/kF0CM0KHbr — BBC News Africa (@BBCAfrica) September 24, 2018

To find out when the video was shot, the investigators analyzed the shadows that each soldier cast. By using a simple equation — powered by the tool Suncalc — the team was able to determine that the murder occurred between March 20 and April 5, 2015.

Notice that the soldiers, like moving sundials, cast shadows on the track. A simple formula tells us the angle and direction of the sun. This corroborates our conclusion on the date, and narrows the timeframe further: the killings happened between March 20 and April 5th 2015 pic.twitter.com/KC8HEvKFuS — BBC News Africa (@BBCAfrica) September 24, 2018

To identify the soldiers in the video, the BBC analyzed the types of weapons they carried and used the Facebook Graph search tool from Michael Bazzell’s OSINT (open-source intelligence) training guide. Then they compared their results against the government’s list of potential suspects.

We put these finding to the government of Cameroon, who said that 7 soldiers have been arrested, disarmed, and imprisoned while under investigation. pic.twitter.com/3zwlmMlaxe — BBC News Africa (@BBCAfrica) September 24, 2018

Strick had done other, smaller investigations before. But this one was different.

“This one, I think, was a huge investigation because we actually saw women and children being murdered. And many of us, it was the first time we saw something happen in Cameroon,” Strick said. “It was probably one of the worst videos I’ve seen — most of us are driven by that passion.”

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It’s a passion that the BBC is keen to capitalize on. Adamson said Africa Eye is building a small team of in-house open-source investigators to work on these kinds of big projects on a more regular basis. But the outlet will continue using freelance work, too.

“We will crowdsource parts of our investigations, where that is necessary, to the open-source community on Twitter and Slack,” he said. “The OSINT community is amazing. Some of those guys are great at weapons analysis, some at geolocation, some at tracking ships or planes … This work is, by its nature, collaborative.”

Beyond finding the right tools, what’s Strick’s advice for other journalists or hobbyists who want to conduct their own digital investigations?

“Do something small, like finding your neighbor’s cat … think like Carrie Mathison from ‘Homeland,’” he said. “That’s the cool thing about this — anyone can jump into this community.”