The Sixth Amendment of the United States Constitution gives a criminal defendant a right to a fair trial. On 21 March 2012, the US Supreme Court ruled that this constitutional right also includes a right to an effective lawyer during plea bargaining negotiations. Consequently, the right of effective counsel in all parts of a criminal proceeding is strengthened by applying it to the entire plea bargaining process.

The US Supreme Court formulated this new standard in two recent cases (Missouri v Frye and Lafler v Cooper), in which legal advice of counsel led the defendant to reject a favourable plea bargain. The Supreme Court argued that had the lawyers counselled the defendants well, they would have taken the shorter sentence. To win a challenge under this new standard, a defendant must show that with effective counsel, he would have taken a plea offer, the judge would have approved it and the deal would have been more favourable than the actual case’s outcome. As such, US Supreme Court case law has changed the plea bargaining process from unregulated negotiations to a procedure under judicial scrutiny.