Over the past two years, prosecutors in the U.S. and Germany have been tracing who was aware of the scheme and have identified more than 40 people involved, spread out across at least four cities and working for three VW brands as well as automotive technology supplier Robert Bosch. In a new, potentially explosive move, some U.S. prosecutors are pushing to indict Volkswagen’s former CEO. Such a step would be largely symbolic — the U.S. has no power to extradite them — but it would send a message that the misconduct was egregious and directed from the top.