The lines between terrorism and criminality are becoming blurred as an increasing number of former criminals join the Islamic State group and create a "gangster jihad," according to a British report released Tuesday, Associated Press reports.
Nearly 60 percent of European jihadists studied by researchers had been jailed previously, in essence creating a "super-gang," said the report from the International Centre for the Study of Radicalization and Political Violence at King's College London.
Once recruited by IS, these people easily transition to committing violence for a different cause, making the group different from other Islamist organisations such as al-Qaida, which often radicalised students, intellectuals or other previously non-violent individuals to carry out its violent aims, the report said.
"They are the perfect fit," Peter Neumann, the centre's director, said. "Islamic State doesn't require any intellectual sophistication. It doesn't ask you to study religion. It makes it all like a computer game."
While past efforts to stop extremist attacks focused on tracing the complicated international bank transactions that financed militants, IS attacks don't necessarily require huge sums of money. The centre estimated that some 40 percent of such plots in Europe are now being financed in part by street crime like selling drugs or counterfeit goods.
One of those involved in the attack on the French satirical magazine Charlie Hebdo financed his activities by selling counterfeit sports shoes on the streets of Paris.
The report suggests law enforcement must target all sources of funding to combat the threat.
"Based on our database, jihadists tend to continue doing what they are familiar with, which means that terrorist financing by criminal means will become more important as the number of former criminals is increasing," the report said.
The researchers warn that European prisons will become more important breeding grounds for the jihadist movement as the number of people convicted of terrorism-related offences increases.
"Institutional silos — for example, the separation between countering crime, customs, and counter-terrorism — need to be broken down," the report said. "With criminal and terrorism milieus converging, the fight against crime has become a national security issue."