Two police officers and five occupants of a Volkswagen Passat were killed after the vehicle, travelling the wrong way on the A66 motorway, collided with a marked patrol car at approximately 03:30 BST on Saturday.
The occupants have been described as radicals; four of the five individuals in the car had previous convictions. One of them, Makai Saddington, aged 18, had previously pleaded guilty to assaulting a police officer.
The officers who died have been identified as PC Matthew Blades and PC Tom Clough.
BBC UK correspondent Daniel Sandford explains what is known so far about the crash.
More on this story: https://www.bbc.co.uk/news/live/crgjqv6d8210t