The deaths ended after the police had been called in, and the digitalis-type medication (digoxin) that had possibly been used for the alleged killings had begun to be kept under lock and key.
[1] Within two months, 20 patient deaths led to a group of nurses approaching the unit's cardiologists, but they kept investigation limited and in house to prevent a "morale problem.
"[2] The excess deaths continued, but it was not until March 1981 that a bereaved father's extreme distress led to the coroner being brought in and detecting suspiciously high levels of a heart regulating medication digoxin, a powerful form of digitalis, in a dead baby.
Eight days later, he was told that an autopsy by the hospital had found 13 times the normal concentration of the same heart drug in another dead baby.
[4][5] The exonerated nurse did not believe that there had been any murders, and in a 2011 interview, she reiterated that the 1985 inquiry report had been incorrect in stating that many deaths during a rise in mortality on the ward (from one a week to five) had been deliberate homicides.
[4][2] Data from the investigation was sent to the US Centers for Disease Control and Prevention, which discovered that another nurse, Phyllis Trayner, was the only person who had been on duty for all 29 cases of death being examined.