Cullen began a three-year stint in the intensive care/cardiac care unit of Hunterdon Medical Center in Flemington. He claimed that he did not harm anyone during the first two years, but hospital records for that time period had been destroyed by the time he was arrested in 2003. Cullen admitted murdering five patients between January and September 1996, again with overdoses of digoxin. He then found work at Morristown Memorial Hospital, but was soon fired for poor performance. Cullen remained unemployed for six months and stopped making child support payments. After seeking treatment for depression in the Warren Hospital emergency room, Cullen was admitted to a psychiatric facility for a short time.