Luigi Mangione pleaded guilty Friday to federal stalking charges in the killing of UnitedHealthcare CEO Brian Thompson, acknowledging in court that he followed the executive to an investor conference before fatally shooting him on a New York City street in 2024.

Mangione, 28, told a Manhattan federal court that he used a 3D printer to make a gun, traveled to New York and posed as an investor at a multibillion-dollar company to obtain information about the conference.

“On the morning of Dec. 4, 2024, I shot Mr. Thompson in Manhattan, and he died,” Mangione said.

He appeared in court wearing a beige jail uniform, shackled at the ankles but without handcuffs.

Thompson’s wife, Paulette, sat in the courtroom and took several deep breaths as Mangione spoke, repeatedly wiping tears from her eyes.