I loved Code of a Killer. Told in three parts, it follows a serial killer who was killing young teenage girls. And you didn’t see who did it, but the way they showed different people, you formed suspicions.
We also learn about Dr. Alec Jeffreys, whose DNA studies were not going well. When a woman asked him to prove her son was her biological child to prevent his deportation, his test actually worked. At the same time, the police were not getting anywhere with solving the murder. When the killer struck again, someone suggested that Jeffreys could help.
Based on the true story of how the police started using DNA to catch killers, Code of a Killer is a very intense, fast paced mystery.