Granito

There has beem a fair amount of debate as to whether documentaries themselves can or, indeed, should effect change - the upcoming Tribeca Film Festival, for example, has a industry talk entitled: Are Documentary Films Changing The World? It's an interesting question and there does seem to be a subtle shift in documentary in recent years, as filmmakers move from simply informing their audience about events to become much more active in terms of pressure being brought to bear.

Recent examples include Oscar-nominated documentary Waste Land, which was made with the express intention of changing the lives of the garbage pickers of Rio de Janeiro. And Granito shows how documentaries can also have a historical impact - even if the filmmaker is not aware of it at the time. As documentarian Pamela Yates puts it: "How does each of us weave our own responsibilities into the pattern of history?"

Back in 1982,Yates travelled to Guatemala to shoot footage for When The Mountains Tremble, intended to be a film about "a hidden war". Looking back at it now, she says: "I had no idea I was filming in the middle of a genocide." But her footage of the Mayan mountain guerrilla movement and, more importantly, of genocidal generals humanitarian lawyers are trying to bring a case against, could have a crucial role in achieving justice for the families of the dead and disappeared.

Yates was approached by lawyer Almedena Bernabau, who asked if she would look through her outtakes for footage featuring, in particularly, Ríos Montt - who went on to be the country's de facto president - to see if there was anything that would bolster the genocide case against him.

This follow-up documentary charts the humanitarian struggle to bring Montt to a court in Spain as well as looking at some of the first and second generation victims of the genocide. Fredy Peccerelli is a forensic anthropologist, unearthing the bodies of the disappeared who were dumped in a pit at a cemetry, Rigoberta Menchu, who told her story in When The Mountains Tremble, has continued to fight for justice for the indigenous people of the country, while one young Guatemalan has perhaps the most personal quest of all - to find out what happened to her 'disappeared' father.

The film is at its best in its footage of those who are picking up the fight that their parents began against Montt, these 'granito' - or grains of sand - who hope that by coming together they can make a difference. Where it falls down is in its rather unfortunate preoccupation with Yates herself. Her voice-over, though personal, feels strangely aloof and footage of her faffing about with the original cannisters of film is unecessarily arty and adds nothing at all to the documentary, serving only to slow it down unecessarily.

If you ignore these odd episodes of unhelpful self-contemplation, however, there is a fascinating story being told, one that bolsters your faith in humanity's desire not just to brush the past under the carpet but to fight for the truth.