Gov. Chris Christie of New Jersey knew that his close associates were involved in a plan to shut down lanes leading to the George Washington Bridge as it was happening and that the closings were intended to punish a local mayor for declining to support him, prosecutors said on Monday.
It was the first time Mr. Christie, a Republican, has been accused of knowing about the scheme as it unfolded.
The prosecutors made the assertion during opening statements in the trial of two former Christie administration officials charged with closing the lanes in 2013 and then covering it up.