The Commission to Investigate Alleged Police Corruption (known informally as the Knapp Commission) became informed of Frank Serpico's police corruption by him doing what?
Frank Serpico:  He is known for whistleblowing on police corruption in the late 1960s and early 1970s, an act that prompted Mayor John V. Lindsay to appoint the landmark Knapp Commission to investigate the NYPD.
i don't know