The 19-year-old man who killed three people and wounded a dozen more at a garlic festival in California before being shot dead by police was inspired by a 19th century racist manifesto written by a New Zealander.
Santino Legan's Instagram account was full of references to the "Might is Right" manifesto written by Arthur Desmond in 1890 - under the pseudonym Ragnar Redbeard.
Susie Ferguson spoke to Historian Mark Derby, who has written a book about Ragnar Redbeard.
