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.

NEW YORK -- Brian Thompson, the CEO of United Healthcare, was shot and killed by a masked man near a Midtown Manhattan hotel early Wednesday, according to police sources. The shooting appears to be targeted but police do not know why, sources said. Thompson was not staying at the Hilton outside of which he was shot, sources said.