In a November 1987 letter claiming responsibility, the group called themselves the "Evan Mecham Eco-Terrorist International Conspiracy" (EMETIC).
A warning letter claiming responsibility for the damage also contained a threat to "chain the Fairfield CEO to a tree at the 10,000 foot level and feed him shrubs and roots until he understands the suicidal folly of treating the planet primarily as a tool for making money."
In May 1989, three people from Prescott, Arizona, Marc Leslie Davis, Margaret Katherine Millet and Marc Andre Baker, were arrested on charges related to the sabotage against the Fairfield Sun Bowl and on conspiracy charges to damage powerlines leading from nuclear power plants in Arizona, California and Colorado.
Short for "Thermite Conspiracy" – thermite being an incendiary mixture of powdered aluminium and iron oxide – Operation THERMCON employed more than 50 FBI agents and involved the infiltration of the group between 1987 and 1989 by undercover FBI agent Michael Fain, and the recruitment of Ron Fraizer, a friend of the three, as an informant.
The operation culminated in the arrest of the three following an attempt to down a transmission tower in the Arizona desert which led from the Palo Verde Nuclear Generating Station.
based in Tucson, Arizona, was not involved in the group but was nonetheless charged with conspiracy, on the grounds that he had given a copy of the book Ecodefense inscribed "happy monkeywrenching" and a $100 donation to undercover agent Michael Fain.
FBI agents also selected the site and purchased and transported cutting equipment prior to the sabotage attempt on May 30, 1989, leading to accusations of entrapment.