One month after leaving St. Barnabas, Cullen took a job at Warren Hospital in Phillipsburg, where he murdered three elderly women with overdoses of the heart medication digoxin. His final victim said that a "sneaky male nurse" had injected her as she slept, but family members and healthcare providers at the hospital dismissed her comments as unfounded. The following year, Cullen moved into a basement apartment in Phillipsburg following a contentious divorce from his wife. He shared custody of his daughters. Cullen would later claim that he had wanted to quit nursing in 1993, but the court-ordered child support payments forced him to continue working.