He was supposed to save lives. Instead, he quietly ended them again and again. Charles Cullen was a nurse, a father, and a trusted caregiver. But behind the sterile walls of hospitals across New Jersey and Pennsylvania, he was something far more terrifying: a serial killer hiding in plain sight. Over a span of sixteen years, Cullen moved from hospital to hospital, leaving behind a trail of suspicious deaths and unanswered questions until the truth could no longer be ignored. A Monster in Scrubs pulls back the curtain on one of the most chilling true crime cases in modern medical history. This book is not just the story of a killer, it's a searing investigation into the healthcare system that enabled him. Through weak oversight, silenced whistleblowers, and institutions that chose self-protection over patient safety, hospitals failed to stop a man they knew was dangerous. With harrowing detail and emotional depth, this story examines how Cullen manipulated medications to murder patients, how warning signs were missed or ignored, and how justice was delayed by the very system meant to protect lives. Through firsthand accounts, legal records, and expert insights, this is a disturbing portrait of evil disguised as compassion and a wake-up call about the fragile trust we place in those who wear the scrubs. A Monster in Scrubs is a reminder that the worst monsters don't always hide in the shadows sometimes, they walk the brightly lit halls of our hospitals.