A nurse at a hospital committed a series of murders; all of her victims were infants and children between the ages of 17 weeks and 11 years. She most frequently injected her victims with potassium chloride, causing cardiac arrest or with insulin, to cause lethal hypoglycemia. When a 15-month-old baby died, staff became suspicious of the number of cardiac arrest deaths in the children’s ward, and so the police were called in.

The investigation ensued, and it was soon discovered that the nurse, who had free access to the necessary drugs, had been the only nurse on duty at the time of each child’s attack. Though the actual number of her victims was not clear, it was established that she murdered four children, attempted to murder three children, and caused grievous bodily harm with the intent to kill six children. What is the most likely psychiatric disorder you suspect for this…