Man charged with killing eight people at Georgia massage parlours

A make-shift memorial is seen outside a business where a multiple fatal shooting occurred (Mike Stewart/AP)

A white gunman has been charged with killing eight people at three Atlanta-area massage parlours in an attack that sent terror through the Asian American community.

Investigators are trying to work out what may have compelled 21-year-old Robert Aaron Long to commit the worst mass killing in the US in almost two years.