As Luigi Mangione faces an upcoming criminal trial as the prime suspect in the murder of United Healthcare CEO’s Brian Thompson, a clear motive has yet to emerge as to why the University of Pennsylvania graduate allegedly shot the insurance executive in broad daylight in December 2024.  In a new Dateline special airing Friday, June 5, at 10 p.m. ET, the news program will dive deeper into the Mangione investigation, speaking with one of Thompson’s close friends, two NYPD Major Case Squad