NEW YORK, Dec. 23 (Xinhua) -- Luigi Mangione pleaded not guilty to New York state murder charges over the shooting of a top UnitedHealth Group executive, as his lawyer expressed concern about getting a fair trial in the high-profile case.

Mangione appeared handcuffed and shackled in a Manhattan court on Monday to be arraigned on multiple counts, including first- and second-degree murder, criminal possession of a weapon, and possessing a forged driver's license.

"Not guilty," the 26-year-old Maryland native, wearing a maroon sweater over a white shirt, Bloomberg News quoted him as saying when he was asked to enter his plea.

Mangione allegedly waited outside a midtown Manhattan hotel before shooting Brian Thompson, the chief executive of UnitedHealth's insurance unit, outside an investor meeting on Dec. 4 with a 3D-printed ghost gun, according to Manhattan District Attorney Alvin Bragg. Mangione then fled, touching off a five-day manhunt that ended with his arrest at a McDonald's in western Pennsylvania. ■