She has tackled injustice and abuse in the film industry and the Catholic church. The Oscar-nominated director reveals why she is telling the shocking story hit podcast Serial failed to cover

The Maryland court of appeals this month overturned a decision to grant Adnan Syed a new trial for the murder of his former girlfriend, Hae Min Lee. The story of Syed’s conviction in 2000 was brought to the world’s attention by the podcast Serial, which launched in October 2014. Its presenter Sarah Koenig examined the evidence against Syed, and steadily built a case that his conviction might have been unsound, though she kept listeners guessing as to her theories about his guilt or innocence until the very end.

Serial was a phenomenon and an unprecedented hit. In 2017, the producers revealed that its episodes had been downloaded over 175m times. Its release coincided with the beginning of the appeals process for Syed, and the decision to deny him a new trial appears to have blindsided everyone involved.

Facebook Twitter Pinterest ‘Warning bells go off’ … Amy Berg. Photograph: David Buchan/Variety/Rex/Shutterstock

“It was a huge surprise,” says the film director Amy Berg. “We’re still processing it right now. It just seemed like he was on the path to winning his appeal. And then it all got turned around.” Berg was nominated for an Oscar in 2007 for Deliver Us From Evil, a film about sexual abuse within the Catholic church. In 2012, she released West of Memphis, which examined the infamous case of the West Memphis Three, who were jailed for murder while teenagers in 1994. Since October 2015, she has been working on The Case Against Adnan Syed, a four-part documentary that serves both as a kind of Serial: What Happened Next, and an attempt to put forward the facts and theories that Serial did not.

Berg is taking a brief break from the edit suite in New York, where she is just finishing the final episode and finding it all rather intense. “Usually,” she says, “you’d finish a film, then take it to the festivals, get a distributor, and have time to make changes. But this is all happening live, so it’s a little bit challenging.” When is the final cut due? “By tonight.”

Berg, who grew up in northern California, has an appetite for telling stories that involve abuses of power and miscarriages of justice. In 2007, she was Oscar-nominated for her first feature film, Deliver Us From Evil, which told the story of Oliver O’Grady, a Catholic priest and convicted paedophile who was “reassigned” to a new area by the church whenever allegations of sexual abuse surfaced.

Facebook Twitter Pinterest Confession … former priest Oliver O’Grady, who admitted past child abuse in Deliver Us From Evil. Photograph: AF archive/Alamy

Berg’s background had been in TV news: “I was looking to transition into long-form after one too many of my many-months-long researched specials were cut down to two minutes.” She had the opportunity to interview O’Grady, and saw potential for a longer film. “The issues around the culture of secrecy and its impact on families and children were of great interest to me.”

Berg returned to similar territory with Prophet’s Prey, about Warren Jeffs, the leader of the Fundamentalist Church of Latter-Day Saints, who is currently serving a life sentence for sexually assaulting children; and again with An Open Secret, which alleged systematic abuse of young boys within the movie industry. Despite Berg’s form as an Oscar-nominated documentarian, when it first appeared in 2015 there were no offers of distribution, no festival invitations. “It is difficult to imagine the Michael Jackson doc or the R Kelly doc getting distribution four years ago,” Berg says.

Facebook Twitter Pinterest Amy Berg talks to Evan Henzi, one of the child performers who spoke out in An Open Secret.

Then, following the Harvey Weinstein scandal, An Open Secret was released on Vimeo in 2017 – for free – and reached 3m views in its first few weeks. The now-defunct Digital Entertainment Network, in which the director Bryan Singer was an early investor, is at the centre of the story. In January this year, a lengthy report in the Atlantic, entitled Nobody Is Going to Believe You, detailed the accounts of a number of men who allege Singer assaulted them when they were underage. Singer continues to deny the claims. Berg says the journalists – Alex French and Maximillian Potter – consulted with her “from the beginning of their arduous journey. I was very happy to have contributed and to see them make it to the finish line.”

West of Memphis examined the case of three Arkansas teenagers who were convicted of murdering three eight-year-old boys in a “satanic ritual”. They were freed in 2011 after almost two decades in prison, and the project created a kind of template for The Case Against Adnan Syed. “West of Memphis was a very fulfilling experience for me as a film-maker and a human being,” she says. “So I guess this case felt like something that would be in the same league.”

It was Serial that first introduced her to Syed’s story. “I was a huge fan. I binged it, intoxicated by the information and the unsettling ending. As a film-maker, I wanted to see a visual story that connected with this case.”

Although her documentary’s title sounds like it might be offering an alternative view to Serial’s, it is a little misleading – because Berg and her team are certainly not arguing that Syed is guilty. “That was just our working title,” she says. “It’s hard to change it once you’ve lived with something for a long time. And we were analysing the case against him, trying to find out did he do it or not. So it stuck.”

When Berg first listened to Serial, it left her feeling that there was a story yet to be uncovered. “When everything is resting on eyewitness testimony,” she says, “and there is a lack of corroborating evidence, warning bells go off for me.” Thanks in part to the hiring of a new team of investigators, who say their aim is to “go beyond anything law enforcement have done”, her series offers new information about that lack of corroborating evidence.

Facebook Twitter Pinterest ‘I did not want the victim to get lost’ … Hae Min Lee.

Berg says she began with only two intentions: “I wanted to bring Hae Min Lee to life. And I wanted to understand the effect this case has had on people.” Hae Min Lee – who was 18 at the time of her murder – is at the centre of Berg’s series. At certain points her diaries, teenage and florid, are made vivid through animated sequences. “Often in true crime stories, the victim gets lost in the quest for what happened to the person who’s been convicted. I definitely did not want that to happen. She was a beautiful young girl whose life was taken. I didn’t want the audience to forget that.”

Lee’s family declined to appear, just as they declined to take part in Serial, though a family friend is interviewed to offer their side. According to a statement released in 2016, they believe that Syed is guilty. “It remains hard,” they said, “to see so many run to defend someone who destroyed our family, who refuses to accept responsibility, when so few are willing to speak up for Hae.”

Berg speaks slowly and carefully when she talks about the family, wanting to be sure to get it right. “I think if there was an injustice here, there are two families that are suffering. I’m trying to find the balance on that. I just can’t imagine how painful it must be for Hae Min Lee’s family.”

Facebook Twitter Pinterest Attorney Rabia Chaudry looks for new connections in The Case Against Adnan Syed. Photograph: HBO/Sky Atlantic

Television is a visual medium and images certainly make some of Serial’s more confusing strands clearer. Berg includes photographs of the site where Lee’s body was buried. For listeners who absorbed the story aurally, it is shocking to see, even briefly. “It’s something that’s used as evidence in the trial,” she says, “and often the documentary becomes kind of a trial. I think it’s important to understand what is being discussed: you’re talking about the crime scene.”

The idea that a documentary might become a kind of trial is, naturally, a difficult one. From Leaving Neverland to Making a Murderer, surely the pursuit of justice on screen raises ethical issues? “I don’t think the ethical issues should rest on the documentarians,” says Berg. “I feel like the ethical issues should be firmly placed on the shoulders of the prosecutors who are unwilling to retry cases. Two courts have said Adnan Syed needs to have a new trial – he needs his day in court.”

The Case Against Adnan Syed: what happened after Serial? Read more

Berg hoped her series would, ultimately, be able to document a new trial. “Now that’s been taken away,” she says. “But I want people to see how the justice system works – then hopefully we will have some changes, because it’s clearly flawed. If there’s one case, then there are hundreds.”

• The Case Against Adnan Syed is out now in the US on HBO; it airs in the UK from 1 April on Sky and Now TV.