H/T to Scott Creighton for pointing me to this passage in an early news account of what happened:
“It began with something not that unusual — a driver with out-of-state plates turning into a blocked entry near the White House.
It quickly became something else.
“Whoa! Whoa!,” Secret Service officers were shouting at the car, according to a witness, Shawn Joseph, 29. “It looked liked [the driver was] scared or lost. I thought they might have been a tourist.”
But then, witnesses said, officers tried to place a barrier in front of the car. The driver swerved. The officers moved the barrier. She hit it, and a Secret Service officer was thrown up on the hood and then off the car.
The officer was not badly hurt. The driver sped east and was stopped by police at a small traffic circle at the foot of Capitol Hill. There, video shot by the U.S.-funded Arabic TV station Alhurra shows officers with guns pointed at the car. The driver took off.”