New details about Luigi Mangione revealed in documentary

The suspect in the ambush killing of UnitedHealthcare CEO Brian Thompson thanked people who have written to him as he is jailed in a New York City detention facility.

Luigi Mangione's statement, posted on a website set up by his defense to provide information about his cases, appear to be his first public comments since he shouted to reporters before a court appearance in Pennsylvania in December.

Mangione is charged in New York with first-degree murder in furtherance of terrorism and other counts in Thompson's Dec. 4 killing. The CEO was shot from behind as he was walking on a Manhattan sidewalk.

Mangione said in the statement that people have written to him at the Metropolitan Detention Center, where he is jailed pending trial.