Charleston shooting: What is the motivation behind a 'hate crime' and why isn't it terrorism?

The FBI has identified 21-year-old Dylann Roof as the suspect in the shooting in Charleston, South Carolina, after his uncle reportedly recognised him from the surveillance camera photo released by police.A picture of Roof on his Facebook profile showed him wearing the Rhodesia (now Zimbabwe) and the South African apartheid flags pinned on his jacket.

Before firing on a Bible study group at the Emanuel African Methodist Episcopal Church, he allegedly said: "I have to do it. You rape our women. You're taking over our country. And you have to go". Shortly after news of the shooting broke, Charleston police chief Greg Mullen said he believed the attack was a hate crime.

Colin Roberts, who leads the research programme on counter-terrorism policing at Cardiff University's UPSI (Universities' Police Science Institute), told IBTimes UK the key question about the Charleston shooting is what catalysed the gunman to carry out the attack.

He said: "They may feel for example that what has happened previously completely justifies or vindicates their world view and they ought to do something. That they're going to make a stand.

"But until we know more about this individual, it's very hard to make any assumptions about it – for example did they have access to right-wing material, what was the motivation? It could be domestic. We don't' know.

"If he has been influenced by extreme far-right material – which is highly available in the US – the question is why now?"