Luigi Mangione, the man accused of shooting dead UnitedHealth Group executive Brian Thompson on a Manhattan street this month, was indicted for murder, New York prosecutors said.
Mangione was indicted on 11 counts, including first-degree murder and murder as a crime of terrorism.
The indictment accused Mangione of murdering Thompson with the intent to "influence the policy of a unit of government by intimidation or coercion."
"This was a frightening, well-planned, targeted murder that was intended to cause shock and attention and intimidation," Bragg told reporters.
Mangione's defence lawyer in New York, Karen Friedman Agnifilo, declined to comment.
Ivy League-educated Mangione was charged with murder on 9 December for the killing of Thompson outside a Manhattan hotel before a company conference, following a five-day manhunt.
Mangione is currently being held on gun charges in Pennsylvania, where he was arrested last week. Bragg said he had indications that Mangione may waive his right to contest his extradition to New York. A hearing over Mangione's extradition is scheduled for Thursday in Pennsylvania.
Mangione suffered from chronic back pain that affected his daily life, according to friends and social media posts, though it is unclear whether his personal health played a role in the shooting.
UnitedHealth Group said last week Mangione was not a customer of the health insurer.
The words "deny," "defend" and "depose" were carved into shell casings found at the Thompson murder scene, several news outlets reported, evoking the title of a book critical of the insurance industry published in 2010 titled "Delay, Deny, Defend: Why Insurance Companies Don't Pay Claims and What You Can Do About It."
Mangione has been celebrated in some circles, and more than a thousand donations have poured into an online fundraiser for his legal defense.
New York Police Commissioner Jessica Tisch said any attempt to rationalize Mangione's alleged actions was "vile."
"There is no heroism in what Mangione did," Tisch told reporters. "We don't celebrate murders and we don't lionize the killing of anyone."
- Reuters