Hunt for the gunman who killed UnitedHealthcare’s CEO heads into third day as new clues emerge

As the investigation into a masked gunman who stalked and killed the head of one of the largest US health insurers moved into its third day Friday, possible leads emerged about his travel before the shooting and a message scrawled on ammunition found at the crime scene. UnitedHealthcare CEO Brian Thompson was killed in a dawn ambush Wednesday as he walked from his midtown hotel to the company’s annual investor conference across the street, blocks from tourist draws such as Radio City Music Hall and Rockefeller Center.