Documentary is a strange beast. Primarily used as a means of visual documentation, but often consumed and produced as entertainment, the documentary film was an educator to you during your youth and continues to inform you to this day, so why would it lie? The medium is perceived as truthful or authentic in its depiction of information, and perhaps has the reputation of being reliable in some way, because that's all we've ever known it to be.

Through editing alone we lose a large amount of authenticity as we will never know what we're not shown, and more more is lost if the subject is aware that they are being filmed. Realistically, the only plausible way a documentary could be considered as 'true' is if the footage was not tampered with or assembled in any way, and if the people that are being filmed had no idea or a motive to alter their normal behaviour. CCTV then, could be considered the purest form of documentary - a true document of reality with no bias, intention or aesthetic design.

The responsibility to be true has nothing to do with the camera however; rather it lies solely with the filmmaker.

The Thin Blue Line (1988) Directed by: Errol Morris

The documentary director holds an immense power over their audience; them dealing with a medium that a viewer believes in and relies on. But they are only human, and a human's capability to remain totally impartial is very limited. Michael Moore's Fahrenheit 9/11 (2004) remains the most financially successful documentary of all time, but has a long Wikipedia page full of criticisms, from a vast range of sources, dedicated to its contextual inaccuracies.

The great documentary makers know that learning is nothing without discussion. Moore composes his films to be one way conversations, a lecture as to why you are wrong and he is right. On the other hand, more celebrated documentarians such as Albert and David Maylses, Werner Herzog, and Joshua Oppenheimer all create a kind of discussion with their audience. I mean this in the sense that their films are certainly more subtle in their methods, but also that they create space for interpretation through their work - The key to your learning and consuming of something being your capacity to interpret it.

Add also Errol Morris to that list, the director of this week's focus film The Thin Blue Line (1988) - a film that remains today an innovation in the form and a momentous occasion in the medium's history. The Thin Blue Line is so good in fact, that it lead to its subjects release from prison.

Fig ii: Morris consistently explores the idea of the spectator's role in the documentary, going as far as showing us his role as a spectator to the case.

Concerning the case of Randall Adams, imprisoned on death row for the murder of a police officer, Morris' film lays out near immaculate evidence that its subject is an innocent man. The film also presents an alternative killer, suggests that five of the jurors in the trial are guilty of perjury, and shows its viewers detailed recreations of the event and the impossibilities of the report.

Though this may damage my argument that documentary is inherently untruthful, the film is a perfect example of the power the documentary film has, one that highlights how a director can utilise the form to enact change and rally opinion, be that the product of either truth or a lie.

Firstly there are the interviews with the people involved in the case. 'Talking head' interviews are a technique that Morris has used throughout his career. But unlike the standard point and shoot talking head interviews prevalent throughout the medium, Morris puts a lot of work into achieving a very specific style of this kind of interview. 'The Interrotron' is a device that Morris himself invented to get his preferred shots (its elaborate method can be seen here) and the results can be seen below (figs iii, iv, v)

Fig iii: Randall Adams, the falsely imprisoned man, looking directly at the audience.

Fig iv: The policeman involved in his questioning, again looking into the camera.

Fig v: David Harris, the 'true' killer. It is important to note that during these interviews Harris rarely looks into the camera, and by extension into Morris or the viewer's eyes.

The device allows the subject of the shot to look directly into camera and the conversation still feel natural. All those interviewed look directly at the audience and talk to us, immediately eliminating the presence of the director whose hand constructs the film. If we remove the director then we remove the accusation of bias, establishing everything that follows as cold hard fact. Or in this case, evidence.

This reinforces the conversational aspect also, making us feel as if they are talking to us rather than through Morris. If we combine this with the complete lack of voiceover (an element often criticised for its omnipotent positioning) then the result is what seems to be the truth, or at least a strong attempt at finding it.

Though both sides may plead their innocence, and the police, politicians and suspects involved all tell you their story, the presence of editing plays a large part in you forming your opinion regarding their credibility. For example, Adams explains to us that when he was first arrested, he was held in a room at gunpoint by a police officer who threatened to shoot him if he did not sign the confession. Immediately after, we cut to the policeman in question, who insists all that had happened between them is what he likes to call a 'friendly conversation'.

If the clips were reversed and we had seen the police officer first, then Adams would have been the punch line to the set up, and his credibility tarnished in a similar way to the policeman's. Through this simple edit the entire character dynamic changes and Morris subtly reinforces his argument without saying a word.

Thirdly are the aforementioned re-enactments, The Thin Blue Line's crowning jewel and perhaps one of the most abstract methods of depicting the 'truth' in documentary. Morris himself has stated that -

"I'd like to point out that reality is re-enacted inside of our skulls routinely, that's how we know about the world"

- And he uses this idea to his advantage in the sense that, by projecting on to the screen his own interpretive process, he simultaneously kick starts the same process in the minds of his viewers. The images in figs vi, vii and viii are all repeatedly shown throughout the film, revisited every time Morris returns to a re-enactment.

Fig vi: The gun coming out of the window, establishing the angle of fire.

Fig Vii: The second officer shooting from behind as the car drives off, later bringing into dispute how good her view of the driver was.

Fig viii: The milkshake that the murdered officer drops, bringing to light the angle he fell after being shot.

By essentially boiling his argument down to three key objects in this case and the evidence their presence results in, he burns them onto the retina of his audience all the while insisting that they consider the case and its flaws. As his viewers are interpreting the facts they have been provided, Morris too does the same, symbolically placing himself amongst the audience and at their level as opposed to being the omnipotent director.

Morris told the truth because he cared. He identified the evidence which he believed cleared Randall Adams' name, presenting it to us because he perceived it as an injustice. The evidence presented came to define much of Adams' argument, and even the theories the film presented beyond the case, regarding state laws and the trial system, were taken into consideration and eventually lead to reform.

However, some documentary filmmakers are not so virtuous. Some are indifferent to the responsibility that comes with the job, and will ignore certain elements to strengthen their case, complement their beliefs and depict something more positively or negatively than it necessarily is. The documentary filmmaker is an artist, not a CCTV camera, and as a result we will never get a wholly truthful or authentic depiction of reality, rather we are shown an interpretation or recreation of it. Not all documentaries lie, but all of their directors have the capacity to, and with this comes a thought. If a documentary was all it took for a man to be spared from death, then what is it capable of in the wrong hands?