Who Was The Killer In Criminal Justice Season 1 -

Warning: Major spoilers for Criminal Justice: Season 1 (BBC One / HBO’s The Night Of) ahead.

If you’ve just finished the first season of the gritty legal drama Criminal Justice (originally created by Peter Moffat for the BBC, later adapted by HBO as The Night Of), you’re likely still processing the overwhelming tension, the moral ambiguity, and the central question that drives the entire plot: Who was the killer?

On the surface, the story follows Adil “Adeel” Akhtar (played by Riz Ahmed in the UK version, and Naz Khan in the US adaptation), a young British-Pakistani man who wakes up to find a woman brutally murdered beside him after a night of drugs and sex. He is arrested, charged, and put on trial for her murder. But as the season unfolds, it becomes painfully clear that nothing in Criminal Justice is as simple as it seems. who was the killer in criminal justice season 1

So, let’s settle the mystery once and for all. Who actually killed Andrea Cornish (or, in the BBC original, Debbie Pemberton)?

Throughout the season, the police and prosecutors build a damning case: Warning: Major spoilers for Criminal Justice: Season 1

But slowly, the defense lawyer, Bernard Forrest, uncovers cracks in the case:

However, none of these pan out as the killer. Mark has an alibi. King was there but didn’t stab her. The show brilliantly subverts the “whodunit” formula by suggesting that the legal system doesn’t actually care who the killer is—only whether they can convict Adil. Throughout the season, the police and prosecutors build

In the original Criminal Justice, the truth emerges not through a detective’s eureka moment, but through the quiet persistence of Debbie’s mother, Mrs. Pemberton.

In Episode 5, Mrs. Pemberton hires a private investigator. They discover that Debbie had recently broken up with a man named Gary, a tall, dark-haired stranger she met at a pub. Gary had a history of violence and had been stalking her.

On the night of the murder, after Adil fled, Gary entered the flat. Debbie was still alive—barely. Gary engaged in a argument with her, then stabbed her repeatedly with a knife from the same block Adil had used earlier. His DNA was found on a cigarette butt at the scene, but the police had ignored it because they were so focused on Adil.

The killer is Gary, a man with no significant connection to Adil. His full face is never shown clearly in the final episode. In fact, the show goes out of its way to make him a shadowy figure—a symbol of the randomness of violence and the blindness of a system obsessed with easy answers.