John C. Kim, known to followers as “Grandmaster ‘Iron’ Kim,” founded the martial arts organization Chung Moo Quan after emigrating from South Korea to the United States in the early 1970s. He opened his first school in Westmont, Illinois, in 1973. Over time, the organization expanded under several names, including Chung Moo Doe and Oom Yung Doe, and promoted a martial art described as “Eight Martial Arts Taught as One.” This system was said to derive from the “1,500-year-old royal line of Chung Moo” and promised benefits such as confidence, longevity, and strength of mind and body.
By the early 1980s, the schools had spread across the U.S., particularly in the Chicago area. The organization described its methods, known internally as “moo doe,” as personalized and distinct from what it called “common martial arts.” Recruitment practices often portrayed the schools as superior training centers offering discounted multi-disciplinary instruction. However, former students later reported that they were pressured into signing long-term, high-cost contracts, sometimes amounting to thousands of dollars, typically paid in cash.
As the organization grew, reports from former members and cult researchers began to surface. They described the schools as highly controlled environments where instructors frequently rotated among locations and allegedly used intimidation to encourage students to purchase advanced courses. One former instructor recalled intentionally creating an atmosphere of fear to persuade students to enroll in black belt programs.
Within the organization, discussions of money were reportedly minimized or coded. Large cash payments were described as gestures of respect toward Kim, and actual sums were sometimes divided by one hundred in speech — saying “one dollar” to mean one hundred dollars — to convey that money held little importance to the founder. Despite this, former instructors said they earned modest annual salaries of roughly $8,000 to $12,000 while the Chicago schools alone were estimated to generate as much as $1.8 million in revenue in 1990. Some former members likened the structure to a pyramid scheme in which funds were concentrated at the top.
Central to Chung Moo Quan’s internal culture was the veneration of Kim. Followers were told stories of his alleged abilities — such as levitation, healing, or influencing others through his photograph — and his infrequent appearances added to his mystique. Reports from former instructors described “loyalty tests,” including being choked until nearly unconscious. Students were also encouraged to adopt distinctive speech patterns, live communally, and devote extensive time to organizational duties. Many said this led to isolation from family, loss of employment, and financial hardship.
By the late 1980s, public scrutiny and legal investigations had intensified. In August 1990, IRS agents raided several schools in Chicago and a ranch in Texas amid allegations of unreported income. Around the same time, the Illinois attorney general filed suit against the organization for violating the state’s Physical Fitness and Consumer Fraud and Deceptive Trade Practices Acts, citing coercive sales tactics and excessive fees.
A major legal turning point came in 1995 when a federal jury convicted Kim and four associates of conspiracy to commit tax fraud. Former members testified that Kim maintained cult-like control over instructors and students while diverting large sums of cash to personal assets, including a Texas ranch and a California home. Authorities estimated that millions in income had gone unreported over two decades. Kim was sentenced to five years in federal prison.
Even after the convictions, tensions persisted between the organization and its critics. In the early 1990s, former students who spoke out reported lawsuits, threats, and occasional violence. One individual said he was physically assaulted after requesting a copy of his training contract, a case later settled out of court.
Following Kim’s release, the organization continued operating under the name Oom Yung Doe, maintaining schools in several states. Leadership attempted to project a more approachable public image, but researchers and former members have asserted that the hierarchical structure and emphasis on loyalty to the organization remain largely the same, including practices that encourage students to prioritize training over their personal lives and careers.
Key Sources:
Janota, L. (1995, April 13). Martial arts schools’ top brass charged with tax fraud. The Chicago Daily Herald.
Johnson, R. D. (2023, August 24). DNA Evidence Cracks Open 39-Year-Old Murder Mystery Involving Former Martial Arts Cult Instructor. Medium.
Johnson, R. D. (2025). Deceived: A True Crime Story.
Vogel, J. (1992, April 1). Be true to your school (The Dark Side of the Moo). City Pages.
Encyclopedia of Cults, Sects, and New Religious Movements 