Final answer:
The role of a defense attorney does not include ensuring an impartial jury, as that is the responsibility of the court, although the defense may participate in the jury selection process.
Step-by-step explanation:
The role of a defense attorney does NOT include ensuring that there is an "impartial jury" of their peers for the defendant. Although defense attorneys have numerous responsibilities, including representing the accused, advising the client, and ensuring their rights are protected, the selection of an impartial jury is typically the responsibility of the court.
Defense attorneys may challenge potential jurors during voir dire (jury selection process) to try to ensure a fair trial, but they cannot directly ensure the impartiality of the jury as that is overseen by the judge. Furthermore, the Assistance of Counsel Clause of the Sixth Amendment and landmark cases such as Glasser v. United States and Gideon's Trumpet have reinforced the right to legal defense.
These rights guarantee that all defendants have access to counsel, meaning a lawyer to represent them. Initially, this was only attainable for those who could afford an attorney, but significant legal cases have expanded this right to include state-provided legal representation for those unable to afford a lawyer.