© Provided by The GuardianPhotograph: Per Arnesen/BBC/misofilm & outline film
The Investigation (BBC Two) has been an elegant series about an ugly crime. Over six sombre, sober episodes, it told the story of the Copenhagen police investigation into what became known as "the submarine case" - the killing of journalist Kim Wall, who disappeared after going to interview a man who built a homemade vessel. It declines to name the killer, a decision that never sits awkwardly, and the gesture is an indication of the respect the series maintains. It is not about glorifying or commemorating the criminal. It is about how he was brought to justice for his crimes.
Within minutes of the first episode, the suspect is arrested and charged with murder, so - much like ITV's recent hit The Pembrokeshire Murders - it is not a whodunnit but rather a puzzle to be solved, at what I imagine is a realistically frustrating pace. Even by the fifth episode, Wall's parents cannot understand why they know as little as they do; the forensic report cannot definitively state the cause of death. Much of The Investigation's drama hinges on precision and detail, as well as the intricacies of the Danish legal system. In the hands of Borgen's Tobias Lindholm, what might sound dreary becomes a clever exercise in building slow, steady peril.
The dour head of homicide, Jens Moller (Soren Malling), and chief prosecutor Jakob Buch-Jepsen (Pilou Asbæk) must between them prove beyond reasonable doubt that Wall was murdered. This means ruling out an accident and suicide, and establishing a motive, which is less straightforward than it first appears. Over the four preceding episodes, the evidence has been amassing, but Buch-Jepsen is able to pick holes in all of it. The case must be utterly solid, and the killer's fantastical and shifting accounts of what happened disproved.
For all of its clinical detail, it is poetically shot. Long scenes unfold without dialogue, ushered along by mournful music, and the killer is only ever a spectral, pathetic presence, changing and twisting his story as more evidence emerges. This, we are told, is his right and does not implicate him. No matter how convincing the circumstantial evidence may be, it is concrete proof that the prosecutor will need. A cause of death would make a conviction all but certain, but given the gruesome events of the murder, it is far from guaranteed.
This feels like a new direction for true crime, an antidote of sorts to the showier serial killer documentaries that seem to be everywhere. There are real human beings at the heart of this saga, and it leaves an appropriate sense of dread in its wake. There are moments of crushing emotion. While Jens' troubled relationship with his daughter felt like one of the few dips into cliche - the detective who cannot leave work behind has been a trope of Scandi-noir - it served its purpose, and his conversation with Jakob, about the horrific randomness of the crime, was devastating. As Jens hugs Ingrid Wall goodbye, now sure that they will be able to convict her daughter's killer, he says, poignantly: "I wish you'd never met me."
© Photograph: Per Arnesen/BBC/misofilm & outline filmUnderstated storytelling . Jens Moller (Soren Malling), Jakob Buch-Jepsen (Pilou Asbæk).
By the end, as most people will know from such an internationally famous case, there is resolution, but anyone expecting a big courtroom showdown will have misread the show. It ends without confrontation, but with text telling us what happened and a series of slow, respectful scenes showing how Kim Wall's family are keeping her legacy alive. To the end, it refuses to name her killer.