How many flashes does a Red Light Camera take?

Question

I was crossing an intersection in New York City. By the time I passed the crosswalk, the light was still yellow but there was a car behind me that also crossed the light. The camera light flashed one and 0.5 to 1 second later flashed a second time. Is there one flash per a vehicle in New York or two per car? Thank you very much.

P.S. This happened on the West St(Westside highway) and Houston street

Answer 1

Its usually two per car.