Dr. Frederick J. Hacker was born and raised in Vienna, Austria. He began attending the University of Vienna, but fled before the Nazis and finished his medical degree at the University of Basel in Switzerland in 1939. In 1940, he emigrated to the United States, where he worked in psychiatric clinics. In 1945, he founded his own clinic, the Hacker Psychiatric Clinic, with offices in Los Angeles and Lynwood, California, and the Hacker Foundation for Psychiatric Research and Education. He became a naturalized American citizen, and after the war he divided his time between California and Vienna. In 1968 he founded the Sigmund Freud Society in Vienna, serving as its president from 1968 to 1977. In 1969, he became well-known as a court-appointed expert in the trial of murderer Charles Manson. He taught at the Department of Psychiatry at the University of Southern California's School of Medicine. In 1972, he worked with the West German government after the terrorist killings at the Munich Olympics, and in 1974, when Patricia Hearst was kidnapped, he worked her family as well. He published several books about aggression and violence. He was a fellow of the American Psychiatric Association.