The recent attack on a Sikh temple in Wisconson has highlighted a disturbing rise in the number of hate groups in the US.
The Southern Poverty Law Centre has tracked an increase from under 600 groups in the year 2000 to 1,018 in 2011.
Experts attribute the increase to a number of events; including 9/11, the election of President Obama, and changing demographics. They say hate crimes are usually motivated by race and religion.
"The sad fact is that Wade Page is just one of thousands of people who're involved in the skin head movement, the neo-nazi movement," said Heidi Beirich from the Southern Poverty Law Centre. "But he decided to step over into violence - most of these people won't - but it's very, very hard to tell when that might happen."
CNN's Susan Candiotti takes a closer look.
