The terrorist drew up to a police car waiting at a red light and opened fire with a Kalashnikov rifle. One officer was killed. Two more were wounded. One seriously enough that there were reports he had died. The terrorism was reportedly also killed. And he was very predictably known to French law enforcement.
That too is a recurring theme.
The attack occurred on the Champs-Elysees near the Franklin-Roosevelt station. The terrorist knew that this would be a good place to find police officers. And it's quite possible law enforcement had been the target all along.
It's unclear what effect the attack will have on the French election since such Islamic terror attacks have become increasingly commonplace.