factual basis for the plea

The judge must determine 'that the conduct which the defendant admits constitutes the offense charged in the indictment or information or an offense included therein to which the defendant has pleaded guilty.' Requiring this examination of the relation between the law and the acts the defendant admits having committed is designed to 'protect a defendant who is in the position of pleading voluntarily with an understanding of the nature of the charge but without realizing that his conduct does not actually fall within the charge.

Defined by the Supreme Court in - McCarthy v. United States, 394 U.S. 459 (1969).