The Twins: A Psychological Thriller - Book 1, #1

They'd survived a living nightmare, only to become living nightmares. Homicide Detective Iris Williams and her partner Detective Andrew Taylor are assigned to a case that will change their lives forever. They are on the hunt for two of the most dangerous, elusive, and youngest serial killers they've ever encountered. Meet 16-year-old, identical twin sisters Stacey and Jannfier McHill and experience revenge like never before.