Killer in the Home

At 09:27 on a Monday morning, a call handler at West Mercia's Operations and Communications Centre receives one of the most chilling calls of her career. A man named Chris Hemming tells her he has just stabbed his ex-partner, Cheryl McKenna, to death in her bed at their Redditch home. Officers arrive within minutes and arrest him. Cheryl, 44, is found dead upstairs. Her 18-year-old daughter Lauren is unharmed in her bedroom, having slept through the attack.

DCI Gareth Lougher leads Operation Trool with a team of 30 detectives and specialists. The killing is not in question, after Hemming himself confessed to the killing on the call. But Gareth knows that establishing exactly what happened, and why, could be critical to the charge Hemming faces and the sentence he ultimately receives.

The forensic examination of the scene offers some early clues: the knife was found in two pieces, the blood evidence suggests a sustained and violent attack, and Cheryl’s bloodstained phone recovered from the kitchen is believed to be the one Hemming used to make his 999 call.

When detectives review the 999 call, they are struck by Hemming's composure. Rather than showing distress, he asks to hang up so he can call his employer to report his absence. DCI Lougher notes this as the behaviour of someone thinking rationally in the immediate aftermath of the killing.

Hemming gives no comment in both interviews and refuses to provide the PIN to his phone. But detectives are building their case without him. Cheryl's daughter describes a household that had become increasingly tense over two years, with arguments about money, the relationship breakdown, and Hemming's growing jealousy over Cheryl's new relationship. She recalls Hemming saying, on more than one occasion, that he felt like killing her mum.

When officers locate body-worn camera footage from a domestic incident four months earlier, they see Hemming is already aware that the relationship was over and that Cheryl had been spending time with someone else. And when forensic software bypasses the PIN on his phone, they find something striking: a note written just six hours before Cheryl's death, in which Hemming describes his rage at being left, and writes that the loss would have been better if she had simply died.

The discovery of a possible tracking device raises further questions about whether Hemming had been monitoring Cheryl's movements in the weeks before he killed her.