Leathy McKnight was 85 when she died at North Horizon Health Center in St. Petersburg, Florida, on November 23, 1984. Her death was one of a string of fatalities at the facility: twelve elderly patients died within a thirteen-day period, most during overnight shifts. Investigators determined McKnight had been given a fatal dose of insulin despite not being diabetic, and similar insulin overdoses were identified in other victims including 97-year-old Aggie Marsh, 85-year-old Stella Bradham, and 79-year-old Mary Rae Carter.

A fifth patient, 94-year-old Anna Larson, survived an insulin overdose but later died of unrelated causes two months afterward. The night-shift nurse on duty during the deaths was 29-year-old Bobbie Sue Dudley (later known as Bobbie Sue Terrell), who had documented mental-health diagnoses and a history of self-harm and fabricating illness. Dudley had exclusive access to insulin, kept notes on patient deaths that were found under her mattress, and staged a stabbing to draw suspicion away. After exhumations and autopsies, she was arrested and charged; in 1988 she pleaded guilty to four counts of second-degree murder, including McKnight’s death, and one count of attempted murder, receiving a 65-year sentence.

Did anyone who worked at North Horizon in 1984 or knew these patients notice unusual activity on the night shifts?