DNA is Not Infallible

DNA is portrayed in movies and real life as the gold standard of evidence. DNA found at a crime scene is incontrovertible proof that the persons whose DNA matches the sample was there. But, what if the odds for certain DNA matches were really only 1 in 3?

This was the case in a recent California rape conviction of a 70-year old man for a crime committed over 30 years ago. Without an eyewitness, without a medical examiners testimony, without the other likely suspect having his DNA tested, and without the victim herself identifying John Puckett as her rapist, he was convicted based solely on flimsy evidence acquired through DNA data mining.

How could that happen? Simply, the prosecution suppressed the real odds and the jury was told the odds of a false match were considerably smaller than 1 in 3. They were told it was 1 in 1.1 million.

The LA Times summaries the semantic tap dancing the prosecution had to go through to secure a conviction:

The chance that two unrelated people will share the same 13 markers can be as remote as 1 in a quadrillion -- a number with 15 zeros. Because the match in Puckett's case involved only 5 1/2 genetic locations, the chance it was coincidental was higher but still remote: 1 in 1.1 million.

But Barlow thought this figure vastly exaggerated the strength of the evidence. It did not take into account how Puckett had been identified: through a search of a large database.

The general-population figures used by prosecutors portray the odds of matching crime-scene DNA to a single, randomly selected person.

But because database searches involve hundreds of thousands or millions of comparisons, experts say using the general-population statistic can be misleading.

Think of a lottery. If you buy a single ticket, your chances of hitting the jackpot are remote. If you buy many tickets, your odds improve with each purchase. In Barlow's view, the prosecution in effect bought hundreds of thousands of lottery tickets to find the match with Puckett. She contended that this greatly increased the odds of a match to an innocent person.

Barlow argued during pretrial hearings that the jury should be told about the recommendation of two leading panels of scientific experts, one convened by the National Research Council and the other by the FBI. Both committees settled upon a statistical remedy to adjust for the many individual comparisons made during a database search. It has been widely but not universally embraced by scientists.

In every cold hit case, the panels advised, police and prosecutors should multiply the Random Match Probability (1 in 1.1 million in Puckett's case) by the number of profiles in the database (338,000). That's the same as dividing 1.1 million by 338,000.

…

Through dueling experts, the prosecution and defense offered jurors a dizzying array of numbers to consider in weighing the DNA match.

A "likelihood ratio" presented by a prosecution expert placed the chance of a coincidental match at 1 in 1.7 million. A "combined probability of inclusion" put it at 1 in 152 billion.

The numbers all pointed to the virtual certainty that the DNA at the crime scene was Puckett's.

In an interview after the trial, Ranajit Chakraborty, the prosecution's DNA expert, told The Times that he generally favors giving jurors the database adjustment. He did not present an adjustment in this case because the judge, like most others, would not allow it.

The full article is well worth reading since it shows the danger of making convictions solely on DNA.

High-tech methods of crime scene analysis will make it important to be increasingly skeptical of the proof presented. It’s only a matter of time before DNA will be taken from every crime scene and analyzed. Around that time it will be the MO of the smart criminal classes to leave someone else’s DNA at the scene to throw the investigators off. The odds may be several million to one that DNA matches, but that shouldn’t mean guilt is certain.

Judge Weinstein Supports Informed Juries

This post and a mess of others on Volokh discuss the new trial granted in US v. Polizzi due to the fact that the jury was not informed of the penalties of the crime. Good.

As we have argued in the past, ignorance is not a basis for law. If a conviction can only be made by keeping juries in the dark then the law is probably not a good one.

(“[M]any disagreements [between judges and juries] are explained by the fact that compared to judges, juries appear to require a stronger case by the prosecution to convict the defendant; or by the fact that juries infuse community notions of justice into their verdicts.” (citing, inter alia, Kalven and Zeisel, supra)). Above all, the experience of trial judges is that the jury is among our most conservative institutions. When in doubt we should trust its judgment, as did those who adopted the Sixth Amendment.

A 'Wire' war vs. the drug war

An excellent and sensible Op/Ed by the creators of HBO's "The Wire."

If enough members of the public signal their disapproval of a law by refusing to enforce it, they might bring about its repeal. That's a happy thought, as long as it is not taken too far. As a rule, it still is better to pass laws in legislatures than in courtrooms.

It is also a good idea, before releasing people for non-violent offenses, to check to see whether they have histories as violent offenders and tendencies to do it again. Many do.

Yet, there is much that we should do to help today's at-risk youth and small-time criminals avoid becoming big-time criminals. For example, we can support neighborhood programs, many of which are church-based, that do a good job of putting kids on the right road. After all, the one thing that is so unsettling about the wasted lives portrayed on "The Wire" is our knowledge that they're not all fiction.

An Op/Ed on Reasonableness in the Criminal Justice System

Canada almost gets it:

First, it sends the message to future mercy killers that they are now more likely to receive an acquittal, even if the law remains unchanged, given the amount of sympathy that exists in the general public for Latimer. In fact, one juror even stated that the jury decision would have been different had they known that Latimer would have to spend so much time behind bars. Given the public outrage at the NPB Latimer decision, "the next Latimer" will likely be held to a lower standard of justice-and juries may even allow him to walk free rather than dole out a draconian
mandatory sentence.

This would be a good thing. The jury is there to protect the people against prosecutors and legislators run amok. If this law is so odious to the population that they would not convict, then the law clearly needs to be changed.

Further, the decision sends a problematic message from a different perspective, which is that if Latimer had lied and showed remorse in front of the NRB, he would have almost certainly been granted parole. This is because the system often rewards supplication, rather than impartiality. However, the problem is that remorse can easily be feigned. This idea has practical implications. Most notably, it has the potential to give rise to false convictions, something that legislators, lawyers and judges alike all fear and abhor. Those wrongly accused will feel more compelled to plea bargain (to confess in exchange for a lighter sentence than if convicted following a full trial) and take their chances with a parole board.

But, prosecutors love this because it makes their job easier. Maybe things are different in Canada, however in the US its accepted that innocent people will admit to something to avoid facing a long list of trumped-up charges. Only the rich can afford to get justice, everyone else is forced to cut a deal since the prosecutor will overcharge to force capitulation.

Although this may be more difficult to remedy, the problem of future juries ignoring the law ("jury nullification") when faced with a sympathetic defendant can be avoided if Parliament should change the law to eliminate mandatory minimum sentences for murder. Mandatory minimum sentences-advocated by those who purport to be "tough on crime"-may actually have the opposite effect, if juries and judges decide to acquit (or convict of lesser and included offences) when faced with sympathetic accused and strict sentencing regimes.

If this paper recognized the need for change and recognizes that nullification will catalyze the process, why do they not advocate nullification?

The War on Juries Continues

Very few things can be more chilling to a potential juror than being hauled up in front of a judge nearly a year after a trial to answer questions about what took place in the jury room.

From the article it seems like nothing will change in this case, but the message is clear: judges don’t hold the jury in very high regard. Clearly, the issue is controversial, however the potentials jurors are supposed to be grilled about their beliefs before the trial, not after. This is near harassment.

Questioning jurors in open court about their deliberations after a verdict is extremely rare. Jury deliberations are considered almost sacrosanct.

"It's extraordinary," said Jonathan Turley, a law professor at George Washington University, who warned that forcing jurors to testify could have a chilling effect.

"The jury system depends on jurors being open and frank in their views. We protect the sanctity of the jury room for that reason," he said.

Jury Rights in Canada

Much the same as in the US; the juries are sovereign but are barred from fully knowing their rights.

Can a trial lawyer inform the jury of its power to nullify? Our law grants jurors the power to nullify, but prohibits counsel from telling them about it.

The law is clear that the defence cannot raise the issue before the jury. Morgentaler dealt with a section of the Criminal Code that restricts the availability of abortions. The defence advised jurors that, if they did not like the law, they need not enforce it. The court said that addressing the jury in this manner would disturb and undermine the jury system.