Polygraph

The Polygraph is a recurring device in Charles Cullen’s legal troubles, but its apparent promise of a readable truth never settles what is at stake. In a custody dispute and later in a criminal investigation, Cullen passes the test. The book sets those results against his knowledge of the bodily rhythms the machine records, and against the widening gap between a recorded physiological response and a convincing account of events.

A Machine Reading the Body

The Polygraph appears in a book preoccupied with the heart as both organ and evidence. During a test, wires connect Cullen’s body to a machine; inked needles trace its results onto graph paper. Those marks include changes in the QRS complex and the frequency of the P wave, familiar measurements to a nurse accustomed to reading electrocardiograms. For Cullen, they are not mysterious signs of an inner truth. They are bodily signals whose movement he understands through his work.

That expertise makes the instrument’s logic feel particularly precarious. Cullen knows that the spikes can be raised or lowered, or stopped altogether. He also knows that drugs used in medical practice, including digoxin, beta blockers, and nitroprusside, can change pulse and rhythm. The book does not establish that he used any drug to manipulate either test. Instead, it emphasizes the disparity between his technical understanding of the recorded signals and the investigators’ simpler interest in changes of pulse and rhythm.

The Divorce-Court Test

The first of the two tests described in the book arose from Charles Cullen and Adrianne Cullen’s divorce proceedings. Adrianne alleged that her husband was a dangerous alcoholic who drank while watching their children. Her request for full custody also relied on a restraining order sought after a domestic-violence call to the police. The test was Cullen’s idea, and arrangements were made on June 18, two months after his release from Greystone Psychiatric Hospital.

According to the machine, Cullen passed and was telling the truth. That result offered him a small success in a conflict that was otherwise going badly in family court. It did not end the dispute: twelve days later, Adrianne was granted a final restraining order. The sequence gives the test a limited, almost paradoxical authority. It produces a favorable result for Cullen, but the court’s eventual action makes clear that the result has not settled the wider question of custody or safety.

The Warren Investigation

A later Polygraph entered the investigation following the death of Helen Dean at Warren Hospital. Her son, Larry Dean, suspected that something was wrong, checked with her doctors and nurses, learned that the male nurse she had identified was Charles Cullen, and called the Warren County Prosecutor’s Office to say that his mother had been murdered. Cullen denied involvement when questioned about the incident. After he went through a suicide cycle involving emergency treatment and psychological care, investigators interviewed him again; when that questioning ended, they brought in the machine.

Cullen regarded the test as medically crude. In his view, investigators were reading basic changes in pulse and rhythm as evidence of truth without understanding the more complex physiological processes beneath them. He knew that the signals were susceptible to changes he could interpret clinically. The Polygraph nonetheless registered a clear pass. Cullen was personally convinced that the investigators knew the truth anyway: the favorable reading had not ended their suspicion or closed the investigation.

What the Results Can and Cannot Establish

Across the two episodes, the test’s meaning changes with the setting. In the divorce proceedings, it gives Cullen a small procedural victory, followed almost immediately by a final restraining order. In the Warren investigation, it offers another apparent exoneration while the inquiry into Helen Dean’s death continues. In neither case does a passing result reconcile Cullen’s account with the actions or suspicions of others.

The device also sharpens the book’s contrast between medical skill and institutional interpretation. Cullen knows how to read the recorded rhythms because he has worked with them professionally; the investigators, as the narrative presents them, seek a simpler answer in pulse and rhythm. Yet that difference does not make the test a reliable window into guilt or innocence. Its traces are bodily measurements, not a full explanation of a person’s actions. The Polygraph therefore recurs less as a decisive detector than as an uneasy emblem of the limits of turning the body into testimony.