Every time a serious or fatal collision happens, hundreds of lives are affected. Behind the flurry of flashing blue lights, and road closures, our team of highly skilled investigators work against the clock to gather evidence, support grieving families and seek the truth.

Tasked with investigating the most serious and fatal road traffic collisions, the Serious Collisions Unit (SCU) see the devastating consequences of poor decision making behind the wheel.

Their work is meticulous, often taking between 12 to 24 months until the culmination of the court process and for a Serious Collision Investigator, every detail matters to provide answers for families left behind.

Sergeant Rob Mazingham, leading the Serious Collision Unit, shares insight on their critical role: “When a collision occurs, the first priority is saving lives. Emergency services work quickly to treat the injured, secure the scene, and ensure there is no further danger to other road users. Once the sirens fade, the investigation begins.

“While officers examine the scene of a fatal collision, Family Liaison Officers are deployed to deliver the devastating news and from that moment, families are thrust into a world of grief, legal processes and unanswered questions.

“Our unit works much like a homicide investigation team. Every mark on the road, fragment of debris or CCTV frame matters. Officers use specialist techniques, including forensic collision reconstruction, vehicle data downloads, and expert analysis to determine exactly what happened in the moments and seconds before impact.

“Each piece of evidence from tyre marks and impact points to phone records and dashcam footage, helps to build a picture of the circumstances and determine whether a criminal offence has been committed. In most cases, the cause is entirely preventable. Distraction, speed, impairment, reckless decisions where one second of bad judgment can have lifelong consequences.

“Unlike other areas of policing, our unit rarely deals with career criminals. Most of the people we investigate are often everyday drivers who made a one-second bad decision behind the wheel.

“They may not have set out to cause a collision, but that doesn’t change the outcome. A moment of inattention, checking their phone, rushing because they’re late, a lapse in judgement during a moment of road rage, a split-second decision causing irreversible devastation to themselves and others.

“If an offence has been committed, whether due to speeding, drink or drug driving, distraction, or careless and reckless behaviour, the case is prepared for prosecution which can take anywhere between 12 to 24 months.

“There are often significant hurdles to overcome, including the need for specialist reports and forensic evidence. This can be incredibly difficult for families who are grieving, and we do everything we can to make sure our investigation is thorough and stands up to scrutiny in court. Our job is to make sure the evidence speaks for itself so they get the justice deserved, but no sentence can ever bring their loved one back or inflict the same suffering that a driver has imposed on the family and themselves.

“Each investigation we carry out serves as a stark reminder how one second can change lives forever. The reality is, most collisions come down to driver choices, speeding, distractions, recklessness and driving under the influence.

“We attend these scenes because of decisions made in seconds. Looking at a phone, pushing the speed limit, driving when tired, taking a risk at a junction. No one leaves their home thinking today will be the day they kill someone on the road, but it happens all too often. And once it does, there’s no going back.”

It takes one second to take a life, one second to ruin your own, one second to lose your job, one second to leave a family grieving forever. Drive safe, every time.

Learn more about our One Second campaign here.