United States — New York City Police Department & Brian Thompson

United States — New York City Police Department: The United States — New York City Police Department investigated the murder of Brian Thompson and obtained intelligence reports indicating Luigi Mangione's motives.

Brian Thompson: Brian Thompson, the CEO of UnitedHealth Group — UnitedHealth Group, was the victim of the alleged assassination by Luigi Mangione. His death was intended to broadcast a message against the health insurance industry and corporate greed.

United States — New York City Police Department: United States — New York City Police Department detectives are investigating Brian Thompson's killing and are receiving evidence from Altoona police.

Brian Thompson: Brian Thompson was the CEO of UnitedHealth Group — UnitedHealth Group and was killed in Manhattan. His murder is the central event of the ongoing legal proceedings.

United States — New York City Police Department: The United States — New York City Police Department was involved in the investigation, arrest of Luigi Mangione, and dissemination of suspect images. Their conduct during the arrest and search is a key point of contention in the defense's efforts to exclude evidence.