999 WHAT HAPPENED NEXT: CHANNEL 4 ANNOUNCES NEW BLUE LIGHT SERIES

This powerful true-crime documentary series follows frontline detectives as they investigate some of the most shocking and complex crimes across the UK. From fatal confrontations on quiet driveways to random acts of street violence, from stalking campaigns driven by obsession to devastating cases of impaired driving, each episode presents two gripping investigations where the truth is buried beneath fear, lies, and chaos.

Through access to real police footage, CCTV, forensic breakthroughs and deeply personal testimony from victims’ families, the series reveals how seemingly ordinary moments can spiral into tragedy. Viewers are taken inside the pressure-cooker environment of major investigations, where officers race against time, evidential uncertainty, and legal constraints to secure justice.

Across four episodes, the series exposes recurring themes of obsession, rage, recklessness and denial — and the devastating consequences they leave behind. Whether unravelling claims of self-defence, tracing violent suspects through city streets, piecing together fragmentary forensic clues, or proving responsibility when suspects refuse to tell the truth, detectives must rely on meticulous police work and determination to bring dangerous offenders to account.

Unflinching, emotionally charged and grounded in real lives forever changed, this series is a compelling exploration of modern policing and the human cost of violent crime.

In the first episode, in the early hours of a summer morning, Suffolk police receive a 999 call from a man claiming to have confronted a thief on his driveway. When officers arrive, the alleged burglar lies fatally wounded nearby. The homeowner insists it was self-defence, a tragic accident in the dark.

But as detectives follow the evidence, CCTV and messages reveal something far more disturbing: a pair who’d long prepared to “take on” local criminals, stockpiling weapons and vowing revenge. Meanwhile in Hertfordshire, a woman wakes to find her car on fire outside her home, and police soon discover she’s been anonymously reported as a drug dealer.

But is she the criminal, or the target of one? Investigators uncover a trail of clues that lead straight to her ex-boyfriend, a man already bound by a Stalking Protection Order. She endures a campaign of lies, threats and arson but is it all due to her ex? Two gripping investigations where police must cut through fear, deceit and obsession to expose the truth and bring dangerous men to justice.

999 What Happened Next begins Tuesday 27th January at 10pm on Channel 4.