NEW YORK (AP) — As the search for UnitedHealthcare CEO Brian Thompson’s killer stretches into a fourth day and beyond the New York City limits, investigators are reckoning with a tantalizing dichotomy. They have troves of evidence, but the shooter remains an enigma. Retracing his steps using surveillance video, it now appears he left the city on a bus soon after the shooting Wednesday morning outside the New York Hilton Midtown. He was seen on video at an uptown bus station about 45 minutes later. The FBI announced late Friday that it was offering a $50,000 reward for information leading to an arrest and conviction. Late Saturday, police released two additional photos of the suspected shooter that appeared to be from a camera mounted inside a taxi. (Photo: AP)