The Donnellys of Biddulph
The Donnellys of Biddulph is a documentary produced by the Canadian Broadcasting System about the Black Donnellys of Canada, an Irish-Canadian family of outlaws, thieves and murderers that are at the root of many legends and stories.
I haven't been able to track down much more about this documentary yet. The IMDB says Duncan plays "Donnelly" but since the legends involve many Donnellys, it's difficult to say which one this means.