Police have yet to determine Fields’ motivation or any planning. But the choice of a car as a weapon in a part of the country where firearms are easily obtainable contrasts with the choices by ISIS or ISIS-inspired attackers in Germany, the UK, and France, where the government tightly restricts gun ownership. ISIS frequently suggests the use of ordinary items by its supporters in attacks, but in the United States the small number of jihadi-related attacks since 2001 have involved firearms or improvised explosive devices. Those have also been the preferred weapons of violent right-wing extremists over the last two decades, according to the FBI.