When a 15-year-old teenager is fatally stabbed in a park in Coventry, the forensics team must identify the murderers through evidence left behind at the crime scene. However, the weapon is nowhere to be found, so they are reliant on just two items - a mobile phone found a short distance from the body and the victim's blood-soaked jacket.

Forensic Investigators from West Midlands Police piece together the evidence in a complex murder inquiry after they find two dead men with unusual wounds.