When a defendant enters a guilty plea, the judge must confirm that the plea is “voluntary and intelligent.” (Courts sometimes use similar terms to convey the same meaning, like “knowing.”) The judge typically speaks directly to the defendant in open court and on the record to make this determination. Judges usually ask defendants whether they are aware of and understand certain rights and facts, such as:
Judges don’t always need to explain the elements of the relevant charges to defendants. Instead, it often suffices for them to confirm that defense attorneys have explained the offenses to their clients. (But see Ineffective Representation in Plea Bargains. Also see Withdrawing a Guilty Plea.)
Example: Pursuant to a deal with the prosecution and the advice of his lawyer, Morgan pleads guilty to second degree murder and the judge sentences him. After, Morgan’s appellate lawyers estbablish that he has substantially below average intelligence, that neither his trial lawyer nor the judge informed him that intent to cause death is an element of the form of second degree murder in question, that the trial lawyer didn’t indicate that Morgan acted with the intent to kill, and that Morgan himself didn’t say anything establishing that he had that intent. The appeals court determines that the plea was involuntary, and that there was a possibility that the homicide was actually manslaughter rather than murder. The plea therefore has to be set aside. (Henderson v. Morgan, 426 U.S. 637 (1976).)
For information on the more fundamental question of whether a defendant is competent to enter a guilty plea, see What is the standard for determining whether someone is competent to plead guilty? And to learn about another determination judges must typically make—sometimes as part of the "voluntary and intelligent" inquiry—see Does a judge have to confirm that the defendant committed the crime before accepting a guilty plea?