Police in San Francisco identified UnitedHealthcare CEO Brian Thompson’s alleged killer, Luigi Mangione, and alerted the FBI four days before his high-profile arrest, a new report says. An officer tipped off the feds after recognizing the 26-year-old’s face in surveillance images put out by the NYPD after Thompson was gunned down last week, sources told the San Francisco Chronicle. Mangione’s face was known to cops in California because he’d been reported missing by his family just weeks earlier on Nov. 18, the sources added.