The investigation into the murder of UnitedHealthcare CEO Brian Thompson has entered its third day, with new clues emerging about the suspect believed to have shot him in New York. Thompson was killed shortly before 7 am local time after leaving a hotel for a conference. Authorities are examining a photo of a person of interest and tracking the suspect's movements, including a Greyhound bus trip from Atlanta. The motive remains unclear, but ammunition found at the scene contained words linked to criticisms of the health insurance industry. Thompson's wife mentioned threats against him prior to the incident.