Luigi Mangione, who was arrested for allegedly killing UnitedHealthcare CEO Brian Thompson, was never a client of the medical insurance company, a New York Police Department (NYPD) official said. According to the police, the 26-year-old Ivy League graduate may have killed the CEO due to the “size and influence” of the company, reported NBC.

Chief of Detectives Joseph Kenny said that Mangione was aware of the company holding its annual investor conference at a Manhattan hotel on December 4 – the day of the crime.

“We have no indication that he was ever a client of United Healthcare, but he does mention that it is the fifth largest corporation in the US, which would make it the largest healthcare organisation in the country. So that’s possibly why he targeted the company…He had prior knowledge that the conference was taking place on that date, at that location,” Kenny told NBC.

Mangione shot the UnitedHealthcare CEO Brian Thompson on December 4 and was since then on the run. The University of Pennsylvania grad led the police on a five-day manhunt, following which he was arrested from a McDonalds in Pennsylvania. He is currently in custody and is facing multiple charges, including murder. Mangione was denied bail at an extradition hearing at the Blair County Courthouse in Pennsylvania on Wednesday.

The suspect was reportedly arrested with a manifesto where he accused health insurance companies of putting corporate greed over the well-being of people – which led to theories that he may have killed the CEO over disappointment with the insurance provider. The police also reportedly found some of Mangione’s writings about wanting to use a gun to target a CEO of a big corporation.

The NYPD found a 3D-printed gun from Mangione – which matched three shell casings found at the crime scene. The 9mm shell casings reportedly had the words “delay”, “deny” and “depose” written across them on each bullet – which were the title of a book criticising the insurance industry.