Milton Rudolph Canter was an 85-year-old patient at Daniel Drake Memorial Hospital in Cincinnati who died on August 29, 1986. Investigators concluded cyanide had been introduced through Canter’s feeding tube; some accounts specify a nasal tube, others a gastric tube, but all agree on cyanide and Harvey’s responsibility.

There was no immediate criminal investigation into Canter’s death at the time. A routine autopsy months later on another patient, John Powell, detected cyanide and set off a wider inquiry that ultimately linked numerous unexplained deaths to Harvey. Harvey later pleaded guilty in Cincinnati to multiple counts of aggravated murder, and Canter was included among the victims covered by those proceedings.