The APA Task Force on Deceptive and Indirect Techniques of Persuasion and Control (DIMPAC) formed at the request of the American Psychological Association (APA) in 1983. The APA asked Margaret Singer, one of the leading proponents of theories of coercive persuasion, to chair a task force to: Singer and her professional associate sociologist Richard Ofshe subsequently sued the APA in 1992 for "defamation, frauds, aiding and abetting and conspiracy" and lost in 1994. Subsequently, judges did not accept Singer as an expert witness in cases alleging brainwashing and mind control.