[1] She induced cardiac arrest in patients by injecting their intravenous therapy bags with lethal doses of epinephrine, commonly known as adrenaline, which is an untraceable heart stimulant.

Prosecutors said Gilbert was on duty for about half of the 350 deaths that occurred at the hospital from when she started working there in 1989, and that the probability of this merely being a coincidence was 1 in 100 million.

In 1996, however, three nurses reported their concern about an increase in cardiac arrest deaths[15] and a decrease in the supply of epinephrine, and an investigation ensued.

[citation needed] [12] In January 1998, Gilbert stood trial for calling in a bomb threat to the Northampton VAMC to retaliate against coworkers and former boyfriend James Perrault (who also worked at the hospital) for their participation in the investigation.

[citation needed][19] Defense attorney David P. Hoose claimed reasonable doubt based on a lack of direct evidence.

William Boutelle, a psychiatrist who served as chief of staff at the Northampton VAMC, has theorized that she created emergency medical crisis situations to display her proficiency as a nurse.

Gilbert forced an untrained colleague to use cardiac defibrillation paddles on a patient during a medical emergency on November 17, 1995, by refusing to use the equipment herself.

[13] While working as a home health aide before becoming a registered nurse and about eight years before her VAMC crimes, Gilbert deliberately scalded a mentally handicapped child with hot bath water.

[24] In July 2003, Gilbert dropped her federal appeal for a new trial after a new US Supreme Court ruling that would have allowed prosecutors to pursue the death penalty upon retrial.