Wow ... not sure how I missed this one for so long, but go check out this trailer for Romasanta right now.
Based on the true story of Manuel Blanco Romasanta, the film tells the story of a mid-1800's travelling vendor convicted of killing thirteen people and using their body fat to make soap. Disturbing enough already, yes? Well get this: Romasanta managed to avoid capital punishment by arguing that he was a werewolf and thus was not responsible for the killings, which he claimed happened while he was in wolf form and not in control of himself.
The film stars Julian Sands and The Machinist's John Sharia and if the trailer is any indicator it's a beautifully atmospheric piece of work. I've got to track this one down ...
Don't have to work hard in order to track this one, it's just been released in the UK a few days ago.