Man pleads not guilty to federal death penalty charge in UnitedHealthcare case

Luigi Mangione is accused of fatally shooting UnitedHealthcare chief executive Brian Thompson in New York City (Steven Hirsch/New York Post via AP)

Luigi Mangione has pleaded not guilty to a federal murder charge in the killing of UnitedHealthcare chief executive Brian Thompson as prosecutors in the US formally declared their intent to seek the death penalty against him.

Mangione, 26, stood with his lawyers as he entered the plea, leaning forward towards a microphone as US District Judge Margaret Garnett asked him if understood the indictment, which charges him with stalking and shooting Mr Thompson outside a Manhattan hotel last December.