Two law enforcement officials say a masked gunman who stalked and killed the leader of one of the largest U.S. health insurance companies on a Manhattan sidewalk used ammunition emblazoned with the words “deny,” “defend” and “depose." The official were not authorized to publicly discuss details of the ongoing investigation and spoke Thursday to The Associated Press on condition of anonymity. The words on the ammunition may have been a reference to tactics insurance companies use to avoid paying claims. UnitedHealthcare CEO Brian Thompson died in a dawn ambush Wednesday as he walked to the company’s annual investor conference. The reason behind the killing remains unknown and the shooter is at large. Images released by police of a person they say is wanted for questioning in connection with the shooting match the lobby of the HI New York City hostel on Manhattan’s Upper West Side. Both feature a black-and-white checkered floor and a distinctive bench in the shape of a semicircle.