Yesterday the world learnt that Bill Cosby’s conviction for three counts of aggravated indecent assault was overturned by the Pennsylvanian Supreme Court.  In essence, the Court ruled that ‘when a prosecutor makes an unconditional promise of non-prosecution, and when the defendant relies upon that guarantee to the detriment of his constitutional right not to testify, the principle of fundamental fairness that undergirds due process of law in our criminal justice system demands that the promise be enforced’.

To make sense of that ruling, we must delve into the history of the Cosby matter.

In 2005, Montgomery County District Attorney (‘DA’) Bruce Castor learned that Andrea Constand had reported that William Cosby had sexually assaulted her in 2004.  In evaluating the likelihood of a successful prosecution of Cosby, the DA foresaw difficulties with Constand’s credibility as a witness based, in part, upon her decision not to file a complaint promptly. Other foreseeable issues also included the fact that there no corroborating evidence to Constand’s accusations.  Because of these considerations, DA Castor concluded that there was insufficient credible and reliable evidence to charge Cosby. This was, unless he confessed.

Running alongside this criminal complaint was also a civil action. Like in criminal trials, a witness or accused is open to prosecution for the crime of perjury if they lie during a civil hearing.

In the United States, when a deposition is taken in a civil case, the Constitutional right against self-incrimination allows a witness to refuse to answer any questions that might lead to criminal liability. But if there is no possibility of a criminal prosecution, then an individual cannot invoke that right and must answer questions.  Cosby relied upon the DA’s declination and proceeded to provide four sworn depositions.  During those depositions, Cosby made several incriminating statements.

However, DA Castor’s successors did not adhere to his decision not to prosecute, and decided to pursue Cosby notwithstanding that prior undertaking.  Those inculpatory admissions were used in the subsequent criminal action against Cosby.  The Supreme Court held that because Cosby had relied upon the undertaking of DA Castor, and that this reliance was ultimately to his detriment, to deny him the benefit of that undertaking was an ‘affront’ to the fundamental notion of fairness in a criminal trial. On that basis the Supreme Court vacated Cosby’s conviction and sentence.

Obviously, the decision is a thought provoking one. It suggests that when an accused suffers detriment due to a promise of a prosecutor, and that detriment is contrary to a longstanding legal doctrine such as the right to silence, the conviction itself may be unsound. This is not to say that the fact of the accused’s guilt is in question. Rather, the conviction was unsafe due to the process through which the inculpatory evidence was obtained.

In Australia, the jurisprudence concerning what constitutes an unsatisfactory or unsafe conviction is vast. While the Cosby decision is no doubt limited by the unique constitutional position of the United States, it’s relevance to the Australian jurisdiction, at the very least, demonstrates the fundamental importance the common law legal system places in long cherished principles such as fairness and the right to silence.