Virginia Gov. Bob McDonnell signed what's known as "Ashley's Law" on Tuesday.
The law requires officers to use lights and siren when they enter an intersection against the traffic light.
The measure comes in the aftermath of a fatal wreck in Alexandria involving a police officer on a cold evening in February 2008. A Fairfax County police officer was in pursuit of a shoplifting suspect north on Route 1. She had her emergency lights on but not her siren when she drove through a red at the intersection with Boswell Avenue and collided with another vehicle.
Ashley McIntosh, a 33-year-old assistant in a Clermont Elementary School kindergarten class, was killed.
McIntosh's mother told News4 if these restrictions had been the law in 2008, this tragedy could have been avoided.