Amy Loughren

Amy Loughren is an American reiki master The patient who triggered law enforcement interest was Florian Gall. As a patient at Somerset Medical, Gall had been improving, then he suddenly died of a massive heart attack. An autopsy showed that he had been administered digoxin. It was not on his prescription list. In small doses, digoxin can improve heart function, but the amount Gall had received was lethal. After consulting with her 11-year-old daughter, Loughren agreed to assist law enforcement.

As part of the investigation into Cullen, Loughren met with him at a diner, wearing a wire. Because she had just had a pacemaker installed, police did not want her to wear the wire, but she insisted. “The truth is I didn’t know how this would affect my heart, but I knew I needed to go in there and get that confession,” she said in an interview with Vanity Fair. During Loughren's meeting with Cullen in the diner, he did not overtly admit to the murders, but he said that he would "go down fighting." and kept working contrary to medical advice. In 2008, Loughren had an experimental heart surgery, and her health has improved. Loughren is played by Jessica Chastain in the movie.

Loughren also was featured in the documentary film Capturing the Killer Nurse, which began streaming on Netflix on November 11, 2022.