The masked assassin who gunned down UnitedHealthcare CEO Brian Thompson outside a luxury Midtown hotel on Wednesday morning was captured seemingly talking on the phone moments before the murder. A man wearing the same dark-colored jacket, hat, ski mask and gray backpack was seen holding a phone to his right ear as he walked east on 54th Street toward the Hilton hotel on Sixth Avenue at around 6:30 a.m., less than 15 minutes before the murder, surveillance footage obtained by ABC 7 shows.