Last month, Bill Cosby's request for parole was denied. On Wednesday, as a result of the decision by the Pennsylvania Supreme Court, he left prison a free man. Not only did the court vacate Mr. Cosby's convictions for sex offenses alleged to have been committed in 2004, but also barred the prosecution from retrying the case. Understandably, members of the #Metoo movement and other victims advocacy groups were outraged. The ruling however, while not a popular one in many circles, was based upon sound legal precedent and should serve as a lesson to prosecutors everywhere.

The grounds for the reversal were basically two-fold. First, that the prosecutor had, in 2005, basically granted Mr. Cosby immunity from prosecution over the claims of sexual assault made by the victim, Andrea Costrand. This was the result of what were perceived as proof problems with the case ( late reported, no physical evidence, lack of corroboration) and part of a trade-off between the state and Mr. Cosby's attorneys that he would agree to testify at deposition in the civil case which had been filed by Ms. Costrand. Secondly, at both criminal trials ( the first one ended in a mistrial), the trial judge permitted extensive testimony for other women who testified that Mr. Cosby had assaulted them in the past in a similar fashion.

Having prosecuted numerous sexual assault cases in the past, I have been faced with the same issues raised in Mr. Cosby's case. Cases involving children and those where the claim is made against a well-known figure where consent may be at issue are often late-reported. Depending how much later, the issues may also include whether the complaining victim has a clear memory of the events, and in this case, whether the allegations were motivated for financial reasons. That being said, if the prosecutor believed there was sufficient evidence to prove the allegations beyond a reasonable doubt, the case should have moved forward. Apparently the Pennsylvania prosecutor did not have sufficient confidence in the available evidence to do so. I would have expected the state, while making a filing decision, to have discussed these issues with Ms. Constrand and her attorneys, especially since they were also proceeding with civil litigation against Mr. Cosby for monetary damages.

The conclusion that Ms. Costrand approved the granting of immunity is additionally supported by the fact that, in exchange, Mr. Cosby later agreed to testify at a deposition conducted by her civil attorneys at which he made a number of admissions regarding the charges, something he would have never done in the absence of the immunity agreement. While the civil case was ultimately settled for $3.38 million, that deposition was later deemed admissible at the subsequent criminal trials. That ruling by the Judge in the criminal trials was deemed reversible error.

At the criminal trials, the prosecution was also permitted to present testimony from other women who also claimed to have been assaulted in the past by Mr. Cosby. Under the proper circumstances and with appropriate safeguards, such evidence is admissible. It is also potentially explosive in nature. Under Florida law, such evidence is commonly referred to as "Williams Rule" evidence, named after the Florida Supreme case which established its admissibility. Such evidence however must not be permitted to become a feature of the trial and is only admitted for the limited purpose of establishing a "common scheme, plan or design" between the prior crimes and the one that defendant is currently charged with. The jury must be instructed that they should accept the evidence for this limited purpose and not merely to show that the defendant is a bad guy or has a propensity to commit such crimes.

Even if the court takes such precautions, most trial attorneys harbor a well-seated fear that ,in spite of jury instructions and the limiting of such testimony, jurors will use Williams rule evidence for whatever purpose they want once deliberations begin. The problem in the Cosby case was that, while the court first approved one such witness, ultimately five witnesses were permitted to testify about being drugged and attacked by Mr. Cosby in the past.

Bottom line, the Pennsylvania Supreme Court did not rule that Mr. Cosby was innocent, or that the complaining witnesses were lying. The court did apply rules which promote fundamental fairness and protect the rights of those accused of any crime, regardless of how serious. While the outcome in this case may rightfully trigger angry responses from those focused on victims' rights, the rule of law was followed. While technically a "free" man, Mr. Cosby will most likely be looked upon as a pariah for the rest of his life. Perhaps a sentence worse than what any judge could impose.