Even though Brian Thompson led one of the biggest health insurers in the U.S., he was largely unknown to the millions of people affected by his decision-making. Wednesday's fatal shooting of the United Healthcare CEO on a midtown Manhattan sidewalk — which police call a targeted killing — thrust the executive and his business into the spotlight.

Calling the incident a “brazen targeted attack,” police said the suspect was waiting for Thompson before shooting him outside of a hotel in Midtown Manhatten. But while authorities stressed that the killing was “premeditated” and planned, the motive for the shooting is still unknown.

Brian Thompson, the CEO of United Healthcare, was killed by a masked gunman outside a hotel in City where he was expected to speak to a ballroom full of colleagues, officials said.

The shooting of the CEO outside of a New York conference center will disrupt the country's largest private healthcare provider.

Brian Thompson was shot in the chest and leg shortly before UnitedHealth was set to hold its annual investors meeting.

Brian Thompson was fatally shot by a hooded gunman as he was walking in the direction of Manhattan's New York Hilton Hotel, a source told BI.

The chief executive of UnitedHealthcare has been shot and killed outside a New York City hotel, AP source says