Posts Tagged ‘DNA evidence’

Taking DNA Samples at Arrest? Not a Problem.

Wednesday, August 4th, 2010

dna

On May 8, 2005, we were having a party.  It was our birthday, and our firstborn had just turned 1 a few days before, so it called for a big celebration with friends and family.  For us, it was a time of new beginnings.  But for Jerry Hobbs, May 8 2005 was the end.  He found his 8-year-old daughter and her 9-year-old friend brutally stabbed to death, in a park in Zion, Illinois.  He immediately called the police, who immediately made him their number-one suspect.  He’d just gotten out of jail in Texas, after all, so why investigate further?  He was subjected to a long, intense interrogation, and eventually made a statement that sounded like a confession.  He recanted the statement, saying it was coerced, but that didn’t matter, and he was charged with the murders.

Shortly after his interrogation, the police found DNA on the girls’ bodies that didn’t match Hobbs.  The DA discounted it, saying it must have been cross-contamination and couldn’t have been relevant to the crime.  But the DNA was in semen found on the girls’ bodies — and inside one girl’s vagina — and that’s not cross-contamination.  The DA insisted that it was still irrelevant, and that the semen must have been on the ground before the attack.  Seriously.  Hobbs remained in custody, charged with the double murder, for more than five years, though his case never went to trial.

He was in jail until a couple of hours ago, that is.  As it happens, that DNA on the girls’ bodies was extremely relevant.  Jorge Torrez, who had lived in Zion at the time, was arrested in Arlington, Virginia a few months back, and charged with the abduction and repeated rape of one woman as well as attacking another woman.  Virginia, unlike Illinois, takes DNA samples along with fingerprints when someone is arrested.  The DNA taken at Torrez’s arrest went into the database, and popped up as a match to the DNA found on the girls.  The Illinois prosecutors dithered for weeks, but this morning they finally released Hobbs from prison (though they refused to issue an apology, insisting they and the police had done everything right).  Still, an innocent man went free at last.

And if Torrez’s DNA had not been swabbed on arrest?  Hobbes’ coerced, false confession might well have resulted in yet another wrongful conviction.

This raises a lot of issues.  There’s the misuse of DNA evidence, and there’s the false confession, but those are topics for another time.  (If you’re interested in learning ways to defend such cases, you can check out our “Hope for Hopeless Cases” CLE series, particularly lectures IV and V.)

Today, however, our beef is with the civil liberties argument against taking DNA samples at arrest.

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The argument is that people who haven’t yet been convicted of a crime should not be compelled to give DNA samples.  It smacks of “Big Brother” and “Minority Report.”  The government might conceivably (more…)

Bacterial Fingerprinting? Don’t Hold Your Breath

Wednesday, March 17th, 2010

bacteria

Over the past couple of days, the news has been filled with stories about using microbes to identify suspects. Everyone has all kinds of bacteria all over their bodies, of course, and whenever you touch something you leave a smudge of your bacteria behind. On Monday, researchers at CU-Boulder published a study where they swabbed computer keyboards, tested the DNA of the bacteria they found, and saw that those bacteria’s DNA more closely matched the bacteria on the computer users’ skin than the bacteria on other people’s skin.

That’s all the study found. The bacteria on your keyboard have DNA that more closely matches the DNA in the bacteria on your fingers, than that of bacteria on other people’s fingers. Frankly, although that’s a nifty result and the scientists deserve to be praised for their work, it’s really a very modest finding. Not exactly earth-shaking.

But as usual, the media took this modest finding and blew it way out of proportion. The study’s authors insist that the project “is still in its preliminary stages.” The media make it sound like we’ll be seeing this stuff in court before we know it. The fact is that using microbial DNA to link a suspect to a crime scene is not going to be a reality any time soon, if ever.

For one thing, there is as yet no reason to conclude that your particular bacteria are as unique as your fingerprints or your personal DNA. Bacteria do not use sexual reproduction, after all, and so their DNA is less diverse than human DNA. The uniqueness of your bacteria is very much an open question.

We don’t even have a baseline of what bacteria are even normal to find on human bodies. A single person will have a huge variety of different microbial populations on different parts of his skin — the microbial mix on his fingertips is not the same as the mix on his nose or his toes. All the various types of bacteria people can have will need to be isolated, all the different DNA each kind of bacterium can have will need to be sequenced, all the various combinations will have to be analyzed, and a massive amount of comparisons will have to be made.

In other words, there will need to be many more studies, based on way more data, plus some pretty robust statistical analyses of large populations, before any scientist can reach the same conclusions as those you’ve been reading in the news. That’s going to take a very long time, even with the accelerating advances in DNA sequencing technology.

Still, it really is an intriguing idea. After all, a perpetrator may not leave behind any blood, sweat or tears. Fingerprints may not be obtainable from fabric or wiped surfaces. But he may still leave behind a smudge of (more…)

Coming Soon: Full-Genome DNA Analysis

Tuesday, March 9th, 2010

This is amazing. Sequencing an entire human genome is now going to be cheap and fast. We predict this will be a game-changing technology for the use of DNA technology.

Right now, DNA evidence is looked at much like fingerprint evidence. With fingerprints, law enforcement doesn’t compare every single ridge and whorl to see if there’s an exact match. Instead, particular locations are compared, to see if those locations are the same. And there’s a lot of subjective interpretation that is needed to make that call. DNA evidence is no different. The entire DNA sequence is not compared. Instead, a handful of locations are compared, to see if the DNA at those locations is the same. And there’s a lot of subjective interpretation that is then needed to make that judgment call. This can call DNA evidence into question, particularly when there are mixtures, degraded samples or equipment glitches that create room for errors of judgment.

If one were to compare the entire genome, however — all 3.3 billion base pairs of it — there would be much less room for interpretation and error.

The problem is that sequencing an entire genome has, to date, been prohibitively expensive. The first genome was a massive undertaking. As of 2009, only 7 people’s genomes had ever been sequenced. The time and expense needed to compare the genomes from a bit of evidence and from a single suspect would take forever and cost a huge amount of money. It’s just not practical.

But if the new technology announced in this WSJ video is for real, all that could change very soon.

If the technology is available to analyze and compare all 3.3 billion base pairs rapidly and cheaply, the current system of comparing 9 or 10 or 13 loci will be woefully inadequate. The current system relies on interpretations that can be incorrect, and statistics that can very easily be (more…)

DNA Evidence: Good Science, Bad Results

Monday, March 8th, 2010

electropherogram-mixture

A couple of weeks ago, we taught another CLE course for the good folks at West Legal Ed Center, in our “Hope for Hopeless Cases” series. This one was on ways to defend cases where the government is going to use DNA evidence to prove your client’s guilt. (Here’s a link.)

DNA evidence can be just devastating. The science is good, after all. And to a lot of potential jurors (and judges and lawyers, unfortunately), “science” is another word for “magic.” Which is another word for “I don’t have to understand how it works, all I know is that it must be so.”

This can often be a wonderful thing, when the science is used correctly, and for the limited purposes to which it is suited. When used correctly, DNA evidence can free the innocent, and help ensure that we really are only punishing the guilty.

The problem is, DNA evidence is all too often used wrong.

And when that happens, the wrong people can get convicted.

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And now today we read a good article in the latest Washington Monthly called “DNA’s Dirty Little Secret: A forensic tool renowned for exonerating the innocent may actually be putting them in prison.” (Link here.)

It’s a good article, about the case of John Puckett, who was convicted in 2008 of an old murder from 1972. It was a brutal rape and murder, with about 20 suspects at the beginning, but the case went cold. Then in 2003 the police tested the DNA found in the evidence. It was old DNA and degraded, and it was also a mixture of multiple people’s DNA. The results were compared to California’s DNA database, and there was a possible match with Mr. Puckett. He hadn’t been a suspect in 1972, but based on this apparent match — and on nothing else — he was prosecuted and ultimately convicted. Jurors have since said that they convicted because of the statistical odds quoted to them at trial, and that if they had known the stats of false positives — which were one in three — they never would have trusted the government’s stats like that.

The article highlights the fact that DNA evidence may be based on good science, but by the time it gets to a jury it can be seriously flawed. Contrary to popular belief, DNA evidence is not objective. It involves a huge amount of subjective interpretation and judgment calls. And whenever human beings have to interpret data and make judgment calls, there is a lot of room for reasonable doubt.

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Contamination, of course, can be a huge issue. Cops screw up when they collect biological evidence, when they stick it in evidence bags, and when they ship it off to the lab. There’s all kinds of opportunities in the real world for a suspect’s DNA to get mixed up with the evidence sample. We’ve worked on at least two cases in the last six months where that is exactly what seems to have happened.

But leaving aside contamination, there are all kinds of ways that experts can look at DNA evidence results and draw the wrong conclusion.

There are technical errors in the lab, for one thing. Sometimes they analyze the wrong evidence. Sometimes the machines doing the analysis aren’t working properly. Sometimes the lab doesn’t test control samples and negative controls, to see if the machines are working right, and whether they’re giving false positives. They almost never do double-blind analysis. Often, analysts will manually adjust the data results, adding or deleting data (!) when it doesn’t look right to them.

There are analytical errors all the time, too. They’re comparing (more…)

Defense to Win All Remaining Supreme Court Cases

Wednesday, June 17th, 2009

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With only two more decision dates remaining in this Supreme Court term, we’ve got our eyes on four criminal cases yet to be decided. Either next Monday (June 22) or the following Monday (June 29), we should expect to hear from the Supremes.

We’re going to make a prediction right now that all four cases will be decided in favor of the defense. Furthermore, we predict large majorities or unanimous decisions in each case. (Go ahead and laugh, we’ll wait for you.)

The four cases are:

Safford USD v. Redding, No. 08-479. We talked about this one before (see here). A public school had an absurd zero-tolerance policy (surprise, surprise), this time prohibiting prescription Advil. A girl got caught with some. She blamed someone else (surprise, surprise). School authorities confronted the other girl, Redding, who denied being involved. They searched her backpack, and found nothing. They searched her clothes, and found nothing.

Now at this point, a reasonable person might have figured out that the girl who was caught with the actual pills was trying to pull a fast one here. But these were not reasonable people — they were public school officials. So they had Redding — a 13-year-old girl — expose her breasts and vagina. They found no pills. Then they shook out her underwear, and found nothing. Then both the school nurse and another school official physically searched the girl’s body. They found nothing.

Now at this point, a reasonable person would have surely figured out that there was nothing to see here. But these bright bulbs instead stuck the girl in the principal’s office alone for a few hours, didn’t contact her folks, and didn’t bother searching anyone else.

The girl sued, claiming (surprise, surprise) that her Fourth Amendment rights had been violated.

The Supreme Court has now been asked to decide whether public school officials are permitted by the Fourth Amendment to perform a warrantless strip search of a student whom they merely suspect of possessing forbidden contraband.

The school wants the Court to say yes, schools can perform strip searches any time they have reason to suspect that a student has forbidden contraband. They want a rule that doesn’t let judges second-guess the judgment of school officials.

Our prediction is that the Court isn’t going to grant such a bright-line rule. For the reasons we set out in our previous post, we predict that the Court will require a case-by-case analysis. It will be fact-specific, whether the officials have evidence that is sufficiently credible to justify an articulable suspicion that contraband will be found during a strip search. And it will require a balancing, to ensure that the invasiveness of the search is proportionate to the danger of the contraband sought. A strip-search to find an explosive is one thing; but examining a young girl’s private parts to find Advil is another thing entirely.

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The next case we’re looking for is Yeager v. United States, No. 08-67.

The issue in Yeager is collateral estoppel after a hung jury. Specifically, a jury acquitted on some counts, and hung on other counts, all sharing a common element. Perhaps the only explanation for the acquittals is that the jury decided that common element in the defendant’s favor. So is the government prevented from re-trying the hung counts, by collateral estoppel?

Yeager was an executive with Enron’s telecom unit, charged with 176 white-collar crimes. After a three-month-long trial, the jury acquitted him on the counts of conspiracy, securities fraud and wire fraud. But the jury hung on the counts of insider trading and money laundering.

The Fifth Circuit said that one explanation for the acquittals is that the jury found that Yeager had no inside information. That was also an element of the insider trading count. But the Circuit said it was impossible to determine “with any certainty what the jury” actually must have decided. So that meant there could be no collateral estoppel precluding a new trial.

At oral argument, Justice Souter honed in on the real issue here, which is a conflict between two underlying principles of our current jurisprudence. On the one hand, once a jury has determined a fact, the government doesn’t get a second chance to prove it. On the other hand, the government is permitted a full opportunity to convict, so it is allowed to re-try counts where a jury hung. Chief Justice Roberts and Justices Kennedy and Breyer explored the conflicting principles in greater depth. Although the government’s attorney was more deft at handling the philosophical argument, and Yeager’s attorney seemed to be stuck in a surface argument, it seemed by the end that the Court was siding with Yeager.

What seems to have killed the government’s position here was its assertion that acquittals should not affect retrials if they are not “rational” — meaning they are inconsistent with the jury’s remaining outcomes — and that a hung count is an outcome that can be used to determine whether the actual verdicts were rational. That not only conflicts with precedent that permits inconsistent verdicts, but also defies common sense by treating the absence of a decision as an affirmative determination.

This one’s a tossup, but we’re going to predict a ruling in favor of Yeager here.

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The third case to watch for is District Attorney’s Office v. Osborne, No. 08-6.

Osborne was convicted 14 years ago for kidnapping and sexual assault. The victim was brutally assaulted and raped in a remote area in Alaska. Osborne was alleged to have used a blue condom. A blue condom was found at the scene, containing semen. Osborne now wants to get discovery of the semen, and have DNA testing done at his own expense, in the hopes that it will demonstrate his innocence. The State of Alaska refused.

Osborne brought a 42 U.S.C. §1983 civil rights suit, arguing that Alaska’s refusal violated his Due Process rights. The district court dismissed the suit, saying he should have brought a Habeas claim instead.

The Ninth Circuit issued two decisions. The first was that a §1983 suit is fine here, because the outcome would not necessarily undermine the state-court conviction. The DNA evidence could potentially prove his guilt, or be inconclusive. It would only require Habeas if the evidence would have to demonstrate innocence. And he could still bring a Habeas later if the §1983 action fails.

In its second decision, the Ninth Circuit forced the Supreme Court’s hand. The Supremes have long taken pains to avoid deciding whether a convict can overturn his conviction based only on a claim of innocence, rather than on pointing out defects in the way the trial was conducted. But the Ninth assumed that this is permissible.

Then, based on that assumption, the Ninth said that in circumstances like that — in fact, only in circumstances like that — where a convict could later use the evidence in a freestanding innocence claim, then Brady gives a post-conviction right to access potentially favorable evidence.

The Supreme Court is now deciding both issues: whether the §1983 suit is appropriate for accessing DNA evidence post-conviction, and whether Due Process requires such access if it could establish innocence.

At oral argument, Justice Souter barely let the Alaska A.G. get a word out before launching a lengthy debate over whether Osborne merely sought evidence that might or might not allow him to establish a claim later, or whether he sought evidence that he affirmatively believes will be the basis of a claim of innocence. By the end, both Scalia and Ginsburg had gotten involved, and the Chief Justice was wondering whether the State even had the evidence any more. Breyer got everyone back on track, pointing out that §1983 was appropriate when you didn’t know what the evidence was yet, and Habeas is appropriate when you do know. And here, nobody knows what the DNA evidence is, yet. So how come the State doesn’t have a constitutional obligation to give him the DNA?

The AG gave a terrible response, saying that Osborne simply followed the wrong procedure. Half the bench jumped in to interrupt him, dumbfounded at the assertion, given that Alaska doesn’t have a statutory procedure in the first place. The one statute out there (as Scalia pointed out) first requires an assertion that the evidence establishes innocence, which is the one thing nobody can say yet, because it hasn’t been tested yet. Souter and Scalia tag-teamed the AG on that mercilessly. At one point, Scalia had the audience laughing at the AG. For the rest of the oral argument, the Justices would refer to the fact that they “must have missed” this procedure being mentioned in any of the briefs.

By the end of the AG’s time, nobody had even gotten to the juicy issues yet. Breyer tried to give the AG a chance to talk about it, but the AG just went back to his procedural claim that had used up his time already. This only frustrated the Justices.

The U.S., as amicus to Alaska, started off better, getting to the heart of the issue — the issue the Supreme Court has so long avoided — arguing that prisoners do not have the right to challenge their conviction based on a freestanding claim of actual innocence. But Souter suggested that the right may be found, “not in procedural, but in substantive Due Process,” and asked a hypothetical about letting counsel speak to another prisoner who claims to have exonerating evidence. The Deputy S.G. floundered, and got laughed at as well. They never even got to the constitutional issue (as Souter repeatedly pointed out), and got mired in whether the government even has an interest here in the first place. And then time was up.

Osborne’s lawyer did much better. He deflected the Court’s concerns that at trial the defense had chosen not to test the DNA, and thus must have believed it would show guilt, by pointing out that both sides chose not to test it, because the tests available would have destroyed all of the evidence, precluding later testing.

The Justices across the board expressed concern that they were being asked to create a new constitutional right here. Shouldn’t a prisoner have to make a claim, under penalty of perjury, that he is actually innocent first? Shouldn’t there be a requirement of due diligence, so that claims aren’t made years and years after they could have been brought? Osborne’s attorney admitted that those are fine ideas, and wouldn’t be an obstacle here.

Then Scalia tipped his hand a little. Osborne’s lawyer observed that this is the first case where a prosecutor conceded that DNA would be “absolutely slam-dunk dispositive of innocence,” but doesn’t let the prisoner access it. Scalia thought out loud, “you know, it is very strange. Why did they do that, I wonder?” “Well, it’s very…” Scalia interrupted, “there was a lot of other evidence in the case, wasn’t there?” “Well, that’s…” Scalia cut in, “I don’t know what they thought they were doing.”

Scalia, for one, is not likely to side with the DA’s office here.

Souter came back to his conclusion that this is a substantive Due Process issue, which would require that the prisoner first claim that he is actually innocent. This conflicted with the sworn testimony before the Parole Board admitting guilt. But Breyer pointed out that prisoners often wisely admit guilt before such Boards, because they’re not getting out otherwise. (As defense lawyers like to say, forget guilt or innocence, “out is out.”) So relying on Parole Board admissions would be an arbitrary basis for withholding DNA evidence. So “suppose we said that the rule is non-arbitrary, with illustrations. Send it back to the states. And of course, when they apply their own statutes, by and large they’re not being arbitrary.” Osborne’s counsel agreed, “I think that’s a very sound approach to this.” Breyer responded, “well, it does help you win.”

I don’t think Breyer or Souter are siding with Alaska here, either.

The Chief Justice wondered if the right would be depend on the accuracy of the testing available. No, said Osborne’s lawyer, it has nothing to do with it — the right would just prohibit the state from arbitrarily preventing access to evidence. So long as there’s a reasonable probability that the test will demonstrate evidence, then that should be enough.

On rebuttal, the AAG got maybe three words in edgewise.

So just going from the oral argument, we’re going to predict a loss for Alaska.

Now whether that means a whole new constitutional right or not, well we’re not so sure. This only affects a handful of defendants whose convictions came before the Federal Innocence Protection Act in the mid-1990s.

The trick, though, will be whether the Court can continue to avoid the elephant in the room, the issue of whether one can assert a freestanding claim of innocence. The Ninth Circuit made it a prerequisite, and both the liberal and conservative Justices seemed to put a lot of weight on whether the prisoner first asserted innocence.

We predict that the Court is going to go all the way here. And as long as we’re going out on a limb, we’ll also predict a unanimous decision.

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The final criminal case yet to be decided is also the oldest: Melendez-Diaz v. Massachusetts, No. 07-591.

The issue is straightforward: Is a lab report, by itself, a form of testimony for Confrontation Clause purposes, per Crawford v. Washington, 541 U.S. 36 (2004)?

Crawford says you can’t introduce earlier statements of a government witness, if they hadn’t been subject to cross-examination.

Well, a police lab report wasn’t subject to cross-examination when it was created. But they are often admitted into evidence without live testimony from the chemist or forensic expert who made the report — they’re self-authenticating. If lab reports are testimonial, then Crawford would preclude this practice. If they are not testimonial, but merely a record, then they could continue to be admitted without live testimony.

The Massachusetts Supreme Judicial Court looked at this conundrum a couple times, and decided that drug analysis reports were simply records of “primary fact, with no judgment or discretion,” by the chemist who prepared them. So they weren’t testimonial, and there was no Confrontation Clause problem.

Melendez-Diaz was the defendant in the second such case, which affirmed the first one.

It’s a sure bet that Scalia is going to side with the defendant here. He has long been a champion of the Confrontation Clause, and his contributions at oral argument were true to form.

The Massachusetts AG was frankly an embarrassment, making inaccurate assertions (and being corrected by the Court), resting heavily on the lame argument that nobody’s made this particular claim before, and claiming that requiring chemists to testify would be an “undue burden,” even though it’s no such burden to California or New York or any other state where it’s routinely done at trial. Kennedy even coached the AG with arguments that she ought to have been making, and scolded her when she still didn’t make them.

Justices Kennedy, Scalia and Stevens had little patience for the amicus Assistant S.G., whose argument was that machine-generated reports aren’t testimonial. There’s a difference between an automated record and a computerized document created for the purpose of proving an element of a crime at trial. And they’re different from computerized documents reflecting the observations and conclusions of a human being.

Based on how the oral argument went, we’re going to predict yet another win for the defendant.

DNA Makes Cops Ignore the Real Evidence, and Chase Shadows

Friday, March 27th, 2009

 

For 16 years, German police have been hunting a fiendish serial killer. Every time they have an unsolved crime, the DNA of an unknown woman has been found at the scene. This phantom killer baffled police with her ability to commit totally unrelated murders without any evidence (apart from traces of her DNA) tying them together.

And when we say “unrelated,” we mean it. The DNA was found on documents at an arson scene, a cop killing, and dozens of other kinds of murders unconnected by geography, motive, means or victim.

Dubbing her “the phantom of Heilbronn,” the cops focused at least 40 investigations in Germany and Austria on identifying this “woman without a face.” When her DNA was found at the scene of a murdered policewoman, a 300,000 (about $375,000) reward was offered for information leading to her arrest.

It turns out, however, that all those unrelated crime scenes DID have something in common, apart from the mystery woman’s DNA. But in all those 16 years, nobody put two and two together.

What did they have in common? The DNA kits used by the cops themselves.

Yup, the swabs used to collect the DNA samples were contaminated. A female worker at the manufacturer apparently wasn’t working under completely sterile conditions, and her DNA was getting on the Q-Tips. As usual, the evidence that made no sense was wrong, and the simplest explanation was the right one.

So the police spent 16 years thinking that her DNA was the DNA of the killer. And instead of focusing on evidence that would have solved these crimes, they followed a wild goose chase that has left nothing but injustice. DNA is the wonder evidence of our time, so when it pointed the way the cops jumped at that conclusion.

Yet another reason why DNA evidence isn’t necessarily as damning as people might think.