Convicted serial killer Charles Cullen is currently serving multiple life sentences at New Jersey State Prison for murdering 29 patients and attempting to kill five others. But a journalist who spent years studying him believes the full story may not yet be known.

Cullen’s crimes, carried out between 1987 and 2003, inspired the book The Good Nurse, written by Charles Graeber. The book later became a film starring Eddie Redmayne. Graeber, one of the few people Cullen agreed to speak with, now questions whether all of the nurse’s victims were ever identified.

Cullen worked at multiple hospitals across New Jersey and Pennsylvania for over a decade before suspicions finally surfaced in 2003. Authorities began investigating after concerns of intentional misconduct and unexplained patient deaths were raised by medical professionals and state officials.

A key breakthrough came when Cullen’s colleague, Amy Loughren, cooperated with investigators. She wore a wire during a conversation with him, leading to a confession where Cullen admitted to killing as many as 30 to 40 patients.

Investigators later determined that Cullen often used lethal doses of medications such as digoxin and insulin, administering them to patients who did not need them. Many victims were difficult to identify due to incomplete records and Cullen’s inability to recall specific names.

Cullen ultimately pleaded guilty to 29 counts of murder and five counts of attempted murder across multiple counties. He avoided the death penalty by cooperating with authorities and helping identify victims where possible.

Despite his convictions, questions remain. A cold case review in 2022 failed to uncover new evidence, but Graeber and others believe there could still be unidentified victims linked to Cullen’s time working in hospitals.

Today, Cullen is serving multiple life sentences, with a parole eligibility date set centuries in the future. His case remains one of the most disturbing examples of medical betrayal in modern history.