The Wikipedia entry on the guy who inspired the creation of Charlie Chan

Wikipedia:

Chang Apana (December 26, 1871 – December 8, 1933) was a Chinese-Hawaiian member of the Honolulu Police Department
...
Chang helped round up people infected with leprosy and send them to a leper colony on the island of Molokai. While performing this duty, Chang was attacked by a Japanese leper with a sickle, leaving him with a distinctive scar over his right eye....One night in Honolulu, with no backup and armed only with his bullwhip, Apana arrested 40 gamblers, whom he then lined up and marched back to the police station.