Now I discover the truth about the "Twinkie Defense":
The expression derives from the 1979 trial of Dan White, a San Francisco, California (U.S.) City Supervisor who shot to death Mayor George Moscone and fellow City Supervisor Harvey Milk on November 27, 1978. During the trial, a noted psychiatrist, Martin Blinder, testified that White had been depressed at the time of the crime, successfully arguing for a ruling of diminished responsibility. As part of this testimony, Dr. Blinder cited White's uncharacteristic eating of Twinkies and drinking of Coca-Cola as evidence of this depression — briefly mentioning that this may also have worsened the depression. The unpopularity of the eventual manslaughter verdict (a lighter sentence which set off the White Night riots) gave rise to the interpretation that White's lawyers had used depression caused by Twinkies as his primary defense. Contrary to popular belief, however, White's defense in fact argued that this consumption was unusual for him and reflected already existing mental instability.