When a man is found dead on a dark mountain road, there’s no sign of a vehicle. With just fragments of debris for clues, the pressure is on to track down the driver that’s fled the scene.

As two young children fight for their lives after their family car is hit by a van on the M4 motorway, the team focus on finding the scene evidence to reveal the devastating truth behind this crash.

When a motorcyclist dies in a crash at a busy city junction, the race is on to find out how the collision unfolded. A man waiting at a bus stop has a lucky escape after a driver loses control.

An 18-year-old man has died in a head-on crash on a country road. As word of the tragedy begins to circulate on social media, a horrifying tale of recklessness is about to be exposed.

When a head-on crash leaves a grandfather dead, Chris discovers the answers could lie in electronic data within the car. As his mission to access it begins, he unearths an intriguing story of what really led up to the crash.

Following the work of Gwent Police's Collision Investigation Unit, the team are alerted to a serious crash by the latest in-car technology, and turn to 3D laser scanning to help establish the facts of what happened. And after a van crashes into a bus shelter, they must find and interpret the evidence to solve the mystery of why the driver lost control.

When a tractor crashes into a family car on a busy city street, officers search for the truth behind the lies and get more than they bargained for when they reconstruct the events of the night.

A road worker is hit by a modified car during a police pursuit. However, when the driver fails to stop, the race is on to track the car down and bring the offender to justice.

Two lorries collide on an industrial estate, leaving one driver injured and investigators searching for answers. But as the evidence is unpicked, one driver's story starts to unravel.

When a woman riding an e-scooter is struck by a car, all viewpoints must be considered. And a crash triggers an automated call from a seriously injured tourist's motorbike.

A meticulous search for evidence is launched to find out why a driver lost control and collided with a lorry on a dual carriageway. Piece by piece, a clearer picture begins to form.

A man is critically injured after he is ejected from a crashing car – but the driver has fled the scene. As a manhunt begins, inquiries take a forensic turn, exposing the chilling truth.

Two men on a powerful sports bike fight for their lives after crashing into a wall. A seriously injured woman is cut free from the wreckage when a car collides with a stationary lorry.

Could CCTV reveal the truth behind a fatal motorbike crash? And after a three-car crash in heavy rain, the team are left stunned by what they discover.