When someone becomes a nurse, they take an oath to do no harm.. But what happens when that oath is broken? Charles Cullen took this same oath when he became a nurse in the late 80s, but what he did over the next 16 years of his career was unspeakable. Charles eventually admitted to killing 40 of the people he was tasked with caring for, however, it’s believed that this number could be much higher.

Sources: 

• 
  https://nymag.com/article/charles-cullen-nurse-serial-killer.html
• https://en.m.wikipedia.org/wiki/Charles_Cullen
• https://www.cheatsheet.com/entertainment/capturing-the-killer-nurse-charles-cullens-case-prompted-37-states-to-adopt-new-laws.html/
• Who Were Charles Cullen's Victims? A Complete Timeline (seventeen.com)
• Charles Cullen | Murderpedia, the encyclopedia of murderers
• The Angel of Death. By Roger Harrington
• Capturing the Killer Nurse. (Netflix, 2022)