This eventually led the hospital's administrator, Charles E. Norris to contact a pharmacist about a discrepancy he had taken note of: during this period, vials of Mivacron had been going missing, which was initially ascribed to inventory mismanagement, as it was not considered a lethal substance.
[7] While exhumations from cemeteries in North Texas and Oklahoma were underway,[4] newspapers revealed that a civil lawsuit had been filed on behalf of one polio patient, 61-year-old Donnelly Reid, who claimed that one of the nurses, Vickie Dawn Jackson, who had since been fired, had injected a drug into his IV tube.
Guerrero had told the jurors that investigators had located vials of Mivacron at Jackson's home, and suggested that her failing marriages and losing custody of her children might have been contributing factors for her decision to start killing her patients.
[11] At her second trial, FBI Special Agent David Burns testified against Jackson, revealing that in the course of several interrogations with her, he determined that she had killed the patients in fits for anger for being "too demanding", and that she had attempted to injure several others, including a 14-year-old girl and a 40-year-old woman suffering from Crohn's disease.
In the end, Jackson pleaded no contest to the ten capital murders charges, accepting the life imprisonment terms in exchange for avoiding a jury trial and having her daughter testifying against her.