United States — New York City Police Department & UnitedHealth Group — UnitedHealth Group

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.

UnitedHealth Group — UnitedHealth Group: UnitedHealth Group — UnitedHealth Group was the target of Luigi Mangione's attack, symbolizing the health insurance industry he aimed to abolish. The company experienced fear among its employees, increased security measures, and threats following the murder of its CEO.

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.

UnitedHealth Group — UnitedHealth Group: UnitedHealth Group — UnitedHealth Group is the company where Brian Thompson served as CEO. The event of his murder and the subsequent trial could affect the company's public image and investor confidence.

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.