Luigi Mangione pleaded guilty Friday in Manhattan federal court to stalking charges tied to the 2024 killing of UnitedHealthcare CEO Brian Thompson, directly admitting for the first time in court that he shot Thompson after researching UnitedHealthcare's December 2024 investor conference and posing as an investor to obtain details about the event. Mangione, 28, told the court he had endured years of severe pain from a broken back and frustrations with the health insurance industry, said he used a 3D printer to make a gun, and confessed that on the morning of Dec. 4, 2024, he shot Thompson in Manhattan. The plea does not appear to be part of a plea agreement. Judge Margaret Garnett accepted Mangione's change from not guilty to guilty after questioning him to confirm he understood he could face life in prison. Thompson's family attended the hearing and later said the plea marked an important step toward justice. Mangione is scheduled to be sentenced on Dec. 18. Prosecutors have recommended a prison term of 24 to 30 years, while the maximum sentence on each of the two stalking charges is life in prison. He still faces separate New York state murder and weapons charges, with trial proceedings scheduled to begin in September.