The Crash Detectives

A huge emergency response is underway on an industrial estate in Croespenmaen in Caerphilly. Two lorries have collided – and while one driver has managed to escape unhurt, the other driver is now seriously injured and trapped in his cab. As desperate efforts to free him get underway, critical care doctors arrive by helicopter, and Dean Burnett and Sergeant Rhys Dickinson are called in to search for answers.

With the amount of activity going on at this volatile scene, they're in no doubt that they could lose vital evidence and must begin a race against time to establish how the two trucks crashed. But as the evidence is unpicked, one driver's story starts to unravel.

Sergeant Cath Raine is on duty when a woman riding an electric scooter is seriously injured in a crash on her way to work in Newport. She's been struck by a car, and with the driver under arrest, all eyes are on Cath to work out what's happened. But when it emerges that the collision has been captured on camera, she's making no assumptions and insists that all viewpoints are considered.

When a crash triggers an automated call from a tourist's motorbike, paramedics and police are quickly alerted to their location in Raglan, Monmouthshire. As the seriously injured rider and pillion passenger are on their way to hospital, PC Richie Wyatt arrives at the scene. But the challenges posed by the tight bend of this slip road mean he's no stranger to investigating here, and the pressure's on to find new evidence relating to this latest collision.

Traffic is at a standstill after an early-morning crash on a busy dual carriageway, near Usk in Monmouthshire, A man driving a Vauxhall Astra has died after his car collided with the rear of a lorry, and Pc Richie Wyatt has been called in to investigate. This scene is littered with debris, and despite a painstaking process to work through it, there are few clues to explain this fatal loss of control.

It's now key to check out the lorry driver's version of events – and focus turns to vehicle tracking data to reveal the true picture of its movements in the lead-up to the collision. But when officers seize dashcam footage captured from the opposite side of the carriageway, it only adds to the mystery of why the driver lost his life.

The race is on to track down a driver who has fled the scene of a serious crash in Newport, leaving his friend critically injured on the road. The victim has been thrown from the back seat of a Volkswagen Polo – and as medics treat him and a seriously injured woman, a manhunt is gaining pace. But for Sergeant Cath Raine and PC Matt Rue, working out how the car collided with a Citroen C3 is proving to be a tough challenge.

With few clues and mounting pressure, they can only hope that the road surface finally decides to give up its clues. With the suspected driver still on the run, the car's onboard data could be about to expose the chilling truth about his actions behind the wheel. But as inquiries take a forensic turn, it transpires that this isn't the only crime he needs to explain.