Two police officers and five people within a Volkswagen Passat travelling the wrong way down the A66 motorway were killed after the car collided with a marked police car around 03:30 BST on Saturday.
Using doorbell footage, pictures of the scene and police reports, we can now piece together exactly how this fatal incident unfolded.
We also know that four of the five people in the car had previous convictions. One of them, Makai Saddington, 18, previously pleaded guilty to assaulting a police officer.
PC Matthew Blades and PC Tom Clough were the two police officers who died in the crash.
The ‘s UK correspondent Daniel Sandford explains what we know so far.