How Did Charles Cullen Kill the Patients, Explained

Image Credit: '60 Minutes'/CBS

Netflix’s crime film ‘The Good Nurse’ revolves around the life of serial killer Charles “Charlie” Cullen, who kills several patients who are admitted to the hospital he works. When the deaths of the patients in the hospital increase alarmingly, Cullen’s colleague Amy Loughren becomes suspicious of the deaths and suspects her fellow nurse’s involvement in the same.

In reality, Amy teamed up with then-Somerset County detectives Tim Braun and Daniel Baldwin to solve the case and bring Cullen to justice. Amy’s efforts played a major role in Cullen’s conviction as well. But how exactly did he kill the patients? Let us explain the serial killer’s modus operandi!

Exploring How Charles Cullen Killed

Charles Cullen killed patients by hacking into the hospitals’ drug protocol. Cullen found a way to procure his “murder weapons” from Pyxis MedStation, an automated medication dispensing system that is used to track and distribute drugs. Nurses use the machine by logging in and requesting the drug one needs. The particular drug’s cabinet will open for the nurses to obtain the same as the request will be recorded in the particular professional’s account. But Cullen found a way to access and obtain the specific drug he needed without the system recording that the same was issued to him.

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Cullen prominently used insulin and digoxin to kill the patients. As per reports, he also used epinephrine on certain occasions. After ordering the drug he wanted, the serial killer would cancel the order request immediately, marking his order “canceled” in his account. Still, the drawer of the drug would open anyway, enabling him to obtain the same without a record that conclusively states that the drug was issued to him.

Cullen’s next step was injecting insulin and digoxin into IV bags that would be administered to patients. “He [Cullen] didn’t have to hide, he didn’t need gloves. He just pulled a 10 ml syringe, popped it from its candylike wrapper, unsheathed the hollow little needle, pop-pop, in and out of the saline. Then, switched bags, pop-pop, into the IVs,” Charles Graeber explained Cullen’s method in his eponymous book, which serves as the source material of the film.

Insulin and digoxin, Cullen’s murder weapons, were normally used to save lives, but they can kill a human being if they were administered without a proper need. “Dig is a very powerful cardiac medication. In small amounts, it slows the heart rate down. In larger amounts, it can cause what’s called complete heart block, and then the heart is very irregular, and you know, it can cause death – it does cause death – in large amounts,” Cullen told Steve Kroft in a ‘60 Minutes’ interview, explaining his selection of the drug. Insulin, on the other hand, sent patients to spiraling diabetic comas.

The officials of New Jersey’s Saint Barnabas Medical Center (presently known as Cooperman Barnabas Medical Center), where Cullen worked right after graduating in nursing, found IV bags with needle pricks in the perimeter, which cannot be an accident. However, they couldn’t bring Cullen to the authorities, which enabled him to continue creating “lethal cocktails” to kill patients. He continued using the same method until he was fired from Somerset Medical Center in Somerville, New Jersey, where he worked with Amy Loughren.

Image Credit: ’60 Minutes’/CBS

When the authorities grew suspicious of Cullen’s involvement in the murders using the drugs he obtained from Pyxis, he tweaked his method. Out of the blue, Cullen’s canceled orders of digoxin and insulin stopped, but the deaths at the hospital continued to happen. Amy went through the Pyxis record and noticed that Cullen had ordered acetaminophen, widely known as paracetamol or Tylenol, multiple times.

Amy wanted to find out why Cullen logged in to Pyxis to get such a common and easily accessible medicine. The nurse ordered the medicine herself and was stunned to see digoxin stored in the same drawer where acetaminophen was kept. Using such tricks, Cullen was able to obtain insulin and digoxin even after the beginning of the investigation. The serial killer’s method was almost flawless until Amy was able to connect the dots and explain to authorities how her co-worker used drugs from the dispensing system to contaminate IV bags that were administered to his victims.

Read More: Is Parkfield Memorial a Real New Jersey Hospital Where Charles Cullen Worked?