NEW YORK (AP) — Brian Thompson led one of the biggest health insurers in the US but was unknown to the millions of people his decisions affected. The fatal shooting of UnitedHealthcare’s chief executive on a midtown Manhattan sidewalk early Wednesday swiftly became a mystery that riveted the nation. Police say it was a targeted killing. Thompson was 50. He had run health care giant UnitedHealth Group Inc.’s insurance business since 2021. It provides health coverage for more than 49 million Americans. He had worked at the company for 20 years. The business run by Thompson brought in $281 billion in revenue last year. Thompson’s $10.2 million annual compensation package made him one of the company’s highest-paid executives.