Because cockfighting is illegal in California, cockfights are held in the strictest secrecy. An HSUS undercover informant, posing as a cockfighting enthusiast, managed to win the confidence of some members of the cockfighting fraternity near Sacramento, California. After several months of undercover work, he was finally invited to a major Derby meet on Sunday, April 23rd. He immediately began arrangements to have the fight raided and participants arrested. Three members of the HSUS Investigations Department, Frantz Dantzler, Phil Steward, and Marc Paulhus, flew to California to set up the raid.
The Humane Society of the United States, "HSUS Investigation Leads to Fifty Arrests in Cockfight Raid" (1978). HSUS Close Up Reports. Paper 8.