Following the discussion of Molineux, the use of prior bad act evidence against a defendant at trial, Gideon at A Public Defender posted an exceptional discussion of the Connecticut Supreme Court decision in State v. DeJesus :

we further conclude that evidence of uncharged misconduct admitted under the liberal standard of admissibility ordinarily does not reflect the existence of a genuine plan in the defendant’s mind. Nonetheless, because strong public policy reasons continue to exist to admit evidence of uncharged misconduct in sexual assault cases more liberally than in other cases, we will maintain the liberal standard, but do so as a limited exception to the prohibition on the admission of uncharged misconduct evidence in sexual assault cases to prove that the defendant had a propensity to engage in aberrant and compulsive criminal sexual behavior.

So what’s the problem with propensity evidence?  For those who may be unfamiliar, propensity evidence is evidence that a person engaged in prior bad behavior and is therefore more likely to engage in bad behavior again.

Propensity evidence comes in two flavors.  Uncharged prior bad acts and prior convictions.  Each presents different problems because it comes into play under different circumstances.  Uncharged prior bad acts can be used affirmatively against a defendant.  Prior convictions, on the other hand, are generally used against a defendant if he testifies, though it is theoretically limited to crimes that reflect upon credibility rather than crimes that suggest that the defendant is a criminal and acted in conformity with his prior criminal  behavior.

The irony of this dichotomy is that uncharged prior bad acts are unproven by definition.  The court is supposed to act as gatekeeper, only admitting those prior bad acts that are shown by “clear and convincing evidence” to have occurred and were performed by the defendant.  This sometimes creates a “trial within a trial,” which puts a defendant in the position of not merely defending against the charged offense, but disproving the uncharged offense as well.

While there are many tactical issues surrounding the fight against prior bad act evidence, one thing is certain.  It is neither proven beyond a reasonable doubt, nor subject to the rigors of due process.  It’s an ugly aside, tossed against a wall to see if it sticks.

In contrast, a conviction is, by definition, proven, even if claimed to be the product of the coercive nature of the system compelling an innocent person to accept guilt rather than fight.  A conviction is a done deal.

But whether the prior bad act is uncharged or a conviction, it has the prejudicial impact of showing that the defendant is a bad person.  It is compelling evidence.  It removes any concern from a juror’s mind that the defendant may be what most people consider an “innocent” person, which is limited to a person who has never committed any “real” wrongdoing.  Once a defendant is a wrongdoer, the step toward conviction is a baby step rather than a giant leap, if for no better reason than he deserves to be punished anyway. 

This is how most of us live our lives and make decisions, including the most important decisions, as jurors are instructed by the court when charged with deciding the burden of proof.  We assume.  We lack both the time and ability to know everything for sure, and we jump to probable conclusions.  We do so without real fear of error, and without any meaningful concern that we are wrong.  Probability rules our decision making process of necessity, and we are quite used to it and comfortable with it.

When a jury is told that the person before them has previously engaged in criminal conduct, it removes a major hurdle from their deliberative process.  They no longer have a reason to doubt that a person is willing to take that step from ordinary person to criminal.  They know that he has already done so. 

Over the years, the expression of this willingness has been refined to frame it in the fashion most damning to the defendant.  While evidence that a defendant had once sold drugs may not be terribly persuasive in a trial for bank robbery, the same evidence framed to show that a defendant is inclined to put his personal financial advantage over the interests of society brings both crimes into alignment.  One suddenly becomes more relevant to the other, and clarifies for the jury why the commission of one suggests the commission of the other.

In short, propensity is incredibly strong evidence of guilt, because we are inclined to adopt simplistic bases for deciding what we believe about others.

So what’s wrong with this?  The fact that a defendant committed 10 prior murders does not mean that he committed this murder.  The duty of the prosecution is not to show that the defendant is a person inclined to murder, but to prove that he committed this specific murder.  This is a variation of Captain Renault’s command to “round up the usual suspects.”  Once it becomes too easy to assume guilt by prior conduct, it eliminates the expectation that any particular crime be proven.  The “usual suspects” become guilty for no better reason than they are the usual suspects.

This helps neither the individual defendant nor society.  Society is not protected when the wrong person is convicted, and obviously the defendant who is innocent of this specific crime isn’t too thrilled about it either.  While it makes for a quick and dirty shortcut to conviction, and one that satisfies the conscience of many a juror, it fails to fulfill the purpose of making certain that the right person is convicted of the specific crime.

For those who believe that the system of convicting people is too burdensome, and are comfortable with the notion that anyone arrested is likely guilty, and are prepared to suffer the potential that some innocent citizens need to “take one for the team” in order to move things along promptly, propensity evidence is the perfect weapon.

For those who believe that it’s important that we not convict the innocent, but demand that only those guilty of the particular crime charged, propensity is a nightmare. 

Of course, my experience is that most people are happy enough to sacrifice a few innocent defendants in order to achieve safety and security from crime, and speed along the process of putting the bad guys in prison.  But then, when asked whether they are willing to be the sacrificial lamb of the legal system’s imperfections, they drop their eyes, shuffle their feet, and pretend they don’t hear.  People are so predictable.