Exeter University's Professor Anthony King has written two books looking at the transformation of football and fan culture in the UK and Europe.
He believes the violence at the Plymouth Argyle - Exeter City match on 9 November 2010 was "highly likely".
He explained that there are generally two kinds of people who create violence at football matches.
"There are the elite, the committed hooligans," said the professor of Sociology at the University of Exeter.
"This group are sometimes dismissed in the press as thugs but they are committed to a special kind of violence.
"More unusual are the completely 'normal' fans who have no pre-meditated desire to get involved who then do get involved - what police call Category B fans.
"They have no prior intention to cause violence but join in once it starts.
"I think there was probably quite a lot of that going on last night."
He says there are three factors which come into play which can lead to trouble.
"The first if if there is some kind of political background to the game, for instance England versus Germany, that informs the game.
"So clearly in this case, as it was a derby, there is that local 'political' dynamic.