Terrorism researchers said that the overtly political nature of the target, and the damage the bomb caused, appeared to meet their criteria for terrorism. But they also said it was unlikely that any suspect would be charged with terrorism, because criminal statutes use more stringent definitions, including the attacker's intent, and can be more difficult to prove. "It appears to be an ideologically motivated act of violence, so that might fall under some definitions of terrorism," said Charles Kurzman, a professor of sociology at the University of North Carolina at Chapel Hill. The researchers also noted that the firebombing of a political office is rare these days, particularly in comparison to the 1960s and 1970s, when such attacks — often committed by left-wing groups — occurred with higher frequency. More recently, in 2000, the Earth Liberation Front started a fire at the Monroe County Republican Party headquarters in Bloomington, Indiana, causing minor damage, according to the Global Terrorism Database, maintained by the National Consortium for the Study of Terrorism and Responses to Terrorism at the University of Maryland.