New analyses undermine perception of DNA infallibility

Rags-against-riches case highlights technology's pitfalls

If you trust in the technology of DNA matching, it was an impeccable case:

Lukis Anderson's DNA matched that found on the fingernails of a San Francisco Bay Area millionaire killed in a home-invasion robbery. Based on the match to Anderson’s sample in the DNA database, the homeless man was arrested on a potential capital murder charge and spent five months in jail.

Fortunately for him, Anderson had an airtight alibi: He was lying in a hospital bed miles away, drunk to the point of unconsciousness. He also had no known connection to Raveesh "Ravi" Kumra, a cell phone entrepreneur and former winery owner who was killed during a home-invasion robbery near San Jose, California.

Although Anderson's attorneys initially thought there might have been a mix-up at the crime lab – the most common cause of erroneous DNA matches – an investigation ruled out improprieties. This despite the fact that, in an ironic twist, the technician who handled the DNA evidence in the case was previously implicated in a crime lab scandal in nearby San Francisco.

Prosecutors think they have solved the mystery: The paramedics who responded to Kumra’s home were the same two who had brought Anderson to the hospital via ambulance about two hours before the home-invasion attack on Kumra began. They likely inadvertently transferred Anderson’s DNA to Kumra via their equipment or clothing.

The local prosecutor called the case unique. But this is far from the first time that cross-contamination has led to a wrongful DNA match.

One of the strangest, most infamous and most embarrassing cases was the "Phantom of Heilbronn." A mystery woman was linked to six murders and dozens of other crimes across Germany and Austria through DNA found on everything from a heroin syringe to a cookie to a stolen car. Desperate police turned to profilers, a monetary reward and even fortune-tellers and psychics to no avail. Finally, after 15 years, the case was cracked: Evidence collection kits had accidentally been contaminated by a worker at a cotton swab factory. Forensic swabs are sterilized, but sterilization does not kill DNA.

In Australia, meanwhile, a 20-year-old man named Farah Jama was convicted and spent time in prison for a rape that likely never even took place. The same forensic officer had collected his DNA in an unrelated matter a day before collecting DNA from a woman who was found unconscious at a Melbourne nightclub. The woman had no recall of events and never claimed she was assaulted; nonetheless, Jama -- who didn’t know the woman and denied ever setting foot inside the nightclub -- spent 15 months in prison before his conviction was overturned.

Potential contamination of DNA evidence also factored into the reversal of Amanda Knox’s conviction in the odd Italian case that received international scrutiny. (Stay tuned on that convoluted case, by the way; the acquittal has now been overturned and a retrial in abstentia is scheduled to begin next month.)

The fact that an airtight alibi did not prevent Alexander from languishing in jail for five months, with a potential death sentence hanging over his head, highlights the problem of blind faith in the reliability of DNA evidence. As Osagie K. Obasogie, a law professor at Hastings School of Law in San Francisco and a senior fellow at the Center for Genetics and Society, argues in a compelling New York Times op-ed:

[T]he certainty with which prosecutors charged Mr. Anderson with murder highlights the very real injustices that can occur when we place too much faith in DNA forensic technologies. In the end, Mr. Anderson was lucky. His alibi was rock solid; prosecutors were forced to concede that there must have been some other explanation. It’s hard to believe that, out of the growing number of convictions based largely or exclusively on DNA evidence, there haven’t been any similar mistakes.

Chance matches more common than thought

But there may be bigger and more ominous problem than the rare transfer errors. The claim that random DNA matches are just about impossible, promoted by crime shows like CSI and powerfully influential in court, turns out to be flat-out wrong. As DNA databases become more and more massive, so too do the odds of chance hits.

An audit of Arizona’s 65,000-profile DNA database turned up almost 150 matching pairs, collected from different people. The California case of John Puckett is frequently cited as an example of misleading over-claiming about the reliability of DNA matches. Puckett is serving life due to a cold hit in a 1972 killing. Jurors heard testimony that there was only a one-in-a-million chance of a coincidental match. But, as Obasogie points out, that figure is misleading, according to an analysis by the National Research Council:

It reflects the chance of a coincidental match in relation to the size of the general population (assuming that the suspect is the only one examined and is not related to the real culprit). Instead of the general population, we should be looking at only the number of profiles in the DNA database. Taking the size of the database into account in Mr. Puckett’s case (and, again, assuming the real culprit’s profile is not in the database) would have led to a dramatic change in the estimate, to one in three.

This overdue recognition of the fallibility of DNA technology is causing some to call for greater oversight and to rethink the idea of allowing convictions based solely upon cold hits from DNA evidence.

Obasogie's final warning is profound:

For far too long, we have allowed the myth of DNA infallibility to chip away at our skepticism of government’s prosecutorial power, undoubtedly leading to untold injustices. In the Anderson case, thankfully, prosecutors acknowledged the obvious: their suspect could not have been in two places at once. But he was dangerously close to being on his way to death row because of that speck of DNA. That one piece of evidence -- obtained from a technology with known limitations, and susceptible to human error and prosecutorial misuse -- might mistakenly lead to execution at the hands of the state should send chills down every one of our spines. The next Lukis Anderson could be you. Better hope your alibi is as well documented as his.

Related blog post: DNA science on trial (April 17, 2009)

Blogger note: As always, it was great meeting blog subscribers during my seminar and training tour at Bond University in Queensland and the American Psychological Association convention in Honolulu. Thanks to all of you who attended and participated. The trainings were great fun; now it's back to the old grindstone as I head home and get back to work.

ABC experiment exposes everyday racial profiling

In the wake of George Zimmerman's acquittal in the killing of Trayvon Martin, some have portrayed the killer as an outlier. But although most people aren't running around shooting down young Black men wearing hoodies, an experiment produced by ABC TV's "What Would You Do?" suggests that racial profiling is more the rule than the exception when it comes to perceptions of crime. 

In the experiment, three people armed with burglary tools sequentially stage the theft of a bicycle chained up in a public park. First, a white teenager. Then, a black one. Finally, a young blond girl tries her luck. Does anyone try to stop them?

Watch the video and be amazed. Then, pass it along.

The discrepancies in public perceptions graphically depicted in this video may help to explain the disproportionate outcomes under Florida's "stand your ground" law, under which it is legal to kill if one believes one is in imminent peril. Since Floridians enacted the controversial law eight years ago, those invoking it have been more likely to succeed if their victim was Black rather than white, according to an analysis by the Tampa Bay Times. About three in four of those who killed African Americans faced no penalty, compared with 6 out of 10 who killed whites.

In a case at least as egregious as Zimmerman's, a white man named Michael David Dunn is awaiting trial for shooting to death an African American teenager, Jordan Davis, at a gas station. Dunn had initiated a confrontation with Davis and his friends over the volume of the youths' music. Rolling Stone ran a moving profile of the case as an exemplar of the racial animus underlying stand-your-ground laws.

An American Psychological Association essay, "After the acquittal: The need for honest dialogue about racial prejudice and stereotyping," provides further resources on this important topic.

This post comes to you from Waikiki, where I arrived this morning from Queensland, Australia in advance of Tropical Storm (now downgraded to Tropical Depression) Flossie. I hope the storm doesn't stop anyone from attending this week's APA convention.

Dispatch from Queensland

Bond University, Robina, Queensland

The blog posts are piling up like jets on a crowded runway, but I haven't been able to carve out the time to send them aloft. It’s been a busy week, lecturing to the criminology and psychology departments at Bond University on Australia's Gold Coast and then giving a training to the College of Forensic Psychologists of the Australian Psychological Society.

The wily kookaburra

Bond is a gorgeous place, designed by an eminent architect in Japan and opened 24 years ago as Australia’s first private university. It caters to a wide range of domestic and international students. The criminology master's program, for example, has students from as far away as Canada, the United States, Iceland and even Grenada.

A fellow tourist captures gorgeous Gold Coast shoreline

The faculty's interests are equally diverse. Raoul Mortley, the Dean of the School of Humanities and Social Sciences, who invited me over as a visiting research scholar, is a scholar of philosophy and the history of ideas. Criminologist Robyn Lincoln, my generous host, has done a slew of fascinating research, including on aboriginals in the criminal justice system, the naming and shaming of juvenile offenders, and wrongful convictions. Currently, she and her students are out riding public buses as part of a research project looking at risks faced by bus drivers. Rebekah Doley, the forensic psychologist who supervises the master’s level psychology students and who graciously organized my career talk to students, and her colleague Kate Fritzon, meanwhile, have launched a pioneering, international institute for the study of arson.

View from Elephant Rock, Carrumba (photo credit: R. Doley)

As during my first trip to Queensland, two years ago for a national forensic psychology conference, I find the country a breath of fresh air – both literally and figuratively. The staff and students at Bond are well informed on local and international issues, and are keen to discuss critical perspectives on the field. (After Americans, Australians form my next-largest subscriber base.)

The infrastructure is so much healthier than in my homeland, with its crippling debt, astronomical incarceration rates, tightening police state apparatus, and legions of homeless roaming the streets. Everything's not perfect; aboriginal incarceration rates are 15 times higher than those of other Australians. (One in every four prisoners here is aboriginal, although aboriginals are only about 2 percent of the population.) But in general, the social safety net is much more solid. Australians find it mind-boggling to hear of an advanced nation without universal health care. Service workers are paid a living wage, so they need not grovel for tips. And I've only seen two presumably homeless people so far, and I've been keeping my eyes peeled.

Lifeguards in training, Broadbeach

It hasn't been all work. As you can see from the photos, I’ve squeezed in a bit of sightseeing and nature viewing. I cycled from my hotel along the Gold Coast to Burleigh Heads one day; another day, Robyn took me into the Hinterlands, to explore a rainforest. (Hence, the kookaburra, who is a consummate thief; just minutes after I got close enough to take this photo, the bird snatched a sandwich from the hands of an unwary little girl.) Watching for migrating humpback whales from my apartment's balcony has also taken up a good deal of my down time.

Sunrise from my apartment

Next up: Honolulu. It’s a rough life.

Most civilly detained sex offenders would not reoffend, study finds

Other new research finds further flaws with actuarial methods in forensic practice

At least three out of every four men being indefinitely detained as Sexually Violent Predators in Minnesota would never commit another sex crime if they were released.

That’s the conclusion of a new study by the chief researcher for the Department of Corrections in Minnesota, the state with the highest per capita rate of preventive detention in the United States.

Using special statistical procedures and a new actuarial instrument called the MnSOST-3 that is better calibrated to current recidivism rates, Grant Duwe estimated that the recidivism rate for civilly committed sex offenders -- if released -- would be between about 5 and 16 percent over four years, and about 18 percent over their lifetimes. Only two of the 600 men detained since Minnesota's law was enacted have been released, making hollow the law's promise of rehabilitation after treatment.

Duwe -- a criminologist and author of a book on the history of mass murder in the United States -- downplays the troubling Constitutional implications of this finding, focusing instead on the SVP law’s exorbitant costs and weak public safety benefits. He notes that "Three Strikes" laws, enacted in some U.S. states during the same time period as SVP laws based on a similar theory of selective incapacitation of the worst of the worst, have also not had a significant impact on crime rates.

The problem for the field of forensic psychology is that forensic risk assessment procedures have astronomical rates of false positives, or over-predictions of danger, and it is difficult to determine which small proportion of those predicted to reoffend would actually do so.

Minnesota has taken the lead in civilly detaining men with sex crime convictions, despite the state's only middling crime rates. Unlike in most U.S. states with SVP laws, sex offenders referred for possible detention are not entitled to a jury trial and, once detained, do not have a right to periodic reviews. Detention also varies greatly by county, so geographic locale can make the difference between a lifetime behind bars and a chance to move on with life after prison.

Ironically, as noted by other researchers, by the time an offender has done enough bad deeds to be flagged for civil commitment, his offending trajectory is often on the decline. Like other criminals, sex offenders tend to age out of criminality by their 40s, making endless incarceration both pointless and wasteful.

The study, To what extent does civil commitment reduce sexual recidivism? Estimating the selective incapacitation effects in Minnesota, is forthcoming from the Journal of Criminal Justice. Contact the author (HERE) to request a copy. 

Other hot-off-the-press articles of related interest:

Risk Assessment in the Law: Legal Admissibility, Scientific Validity, and Some Disparities between Research and Practice 

Daniel A. Krauss and Nicholas Scurich, Behavioral Sciences and the Law

ABSTRACT: Risk assessment expert testimony remains an area of considerable concern within the U.S. legal system. Historically, controversy has surrounded the constitutionality of such testimony, while more recently, following the adoption of new evidentiary standards that focus on scientific validity, the admissibility of expert testimony has received greater scrutiny. Based on examples from recent appellate court cases involving sexual violent predator (SVP) hearings, we highlight difficulties that courts continue to face in evaluating this complex expert testimony. In each instance, we point to specific problems in courts’ reasoning that lead it to admit expert testimony of questionable scientific validity.We conclude by offering suggestions for how courts might more effectively evaluate the scientific validity of risk expert testimony and how mental health professionals might better communicate their expertise to the courts.

Contact Dr. Krauss (HERE) for a copy of this very interesting and relevant article. The following two articles are freely available online:

The utility of assessing "external risk factors" when selecting Static-99R reference groups

Brian Abbott, Open Access Journal of Forensic Psychology

ABSTRACT: The Static-99 has been one of the most widely used sexual recidivism actuarial instruments. It has been nearly four years since the revised instrument, the Static-99R, has been released for use. Peer-reviewed literature has been published regarding the basis for changing the scoring system for the age-at-release item, the utility of relative risk data, and variability of sexual recidivism rate s across samples. Thus far, the peer-reviewed literature about the Static-99R has not adequately addressed the reliability and validity of the system to select among four possible actuarial samples (reference groups) from which to obtain score-wise observed and predicted sexual recidivism rates to apply to the individual being assessed. Rather, users have been relying upon the Static-99R developers to obtain this information through a website and workshops. This article provides a critical analysis of the reliability and validity of using the level of density of risk factors external to the Static-99R to select a single reference group among three options and discusses its implications in clinical and forensic practice. The use of alternate methods to select Static-99R reference groups is explored.

Calibration performance indicators for the Static-99R: 2013 update

Greg DeClue and Terence Campbell, Open Access Journal of Forensic Psychology

ABSTRACT: Providing comprehensive statistical descriptions of tool performance can help give researchers, clinicians, and policymakers a clearer picture of whether structured assessment instruments may be useful in practice. We report positive predictive value (PPV), negative predictive value (NPV), number needed to detain (NND), and number safely discharged (NSD), along with associated confidence intervals (CIs) for each value of the Static-99R, for one data set. Values reported herein apply to detected sexual recidivism during a 5-year fixed follow-up for the samples that the Static-99R developers consider to be roughly representative of all adjudicated sex offenders.

BLOGGER NOTE: I'm posting this research update while stranded at LAX en route to Brisbane, Australia, where I will be giving a series of seminars and trainings at Bond University before flying to Honolulu to give a full-day continuing education training at the American Psychological Association convention. (Registration for that is still open, I am told.) I'll try to blog as time allows, and I hope to see some of you at these venues.

Summer reading, and more

My regrets for the dearth of blog posts as of late. I am feverishly working to prepare all of my upcoming seminars and trainings (while keeping up with forensic case work!). I hope to see some of you next month, either in Honolulu (at my APA workshop) or at Bond University in Queensland, where I will be hosting seminars and a forensic training. I hope to bring you blog posts about these and other experiences, as time allows. In the meantime, here are a few snippets and recommendations for summer reading:

High Price: A neuroscientist’s journey of self-discovery that challenges everything you know about drugs and society 

You have probably heard of the rat studies in which rats -- allowed to press a lever to get either drugs or food -- will repeatedly choose drugs, thereby starving themselves. What you may not know is that those rats are locked in little cages all by themselves, with no friends or partners and nothing to do. Give them a pleasant life -- buddies to pal around with, cuties to hook up with, and games to play -- and they don't get strung out. It would be like running a drug study on prisoners in solitary confinement, and then claiming that your results generalize to the free world.

This is one of the more illuminating examples in Harvard psychology professor Carl Hart's new page-turner, High Price. Hart's goal is to show that current U.S. drug policy is more about racism than brain science. Unusually, his vehicle for this message is a memoir rather than an academic text. It's a courageous memoir, in which he describes his own background and upbringing in a rough section of Miami, Florida. The book is weighted more toward autobiography than the scientific research, but is quite intriguing nonetheless, illuminating the chance factors that shape our lives, and the destructive impact of drug laws on African American communities in particular.

Hart also describes studies by him and his colleagues at Columbia, in which they recruited cocaine and methamphetamine addicts to live in a lab for a couple of weeks, and get paid to take high-quality drugs. Not a bad deal. Again contrary to the dominant messages about zombie drug fiends (think of those fried-egg ads about "your brain on drugs"), the addicts made quite rational choices about whether and when to take drugs, thereby highlighting the potential for rehabilitation.

My Amazon review is HERE; video interviews with the author can be viewed HERE.

The other Wes Moore: One name, two fates

Speaking of the chance factors in life (and also drugs, race and memoirs), I have just been listening to the audio version of a fascinating book about two young Black men with the same name and similar backgrounds, both with ties to the same troubled section of drug-plagued Baltimore (think The Wire). One grew up to become a Rhodes Scholar, decorated veteran, White House Fellow and business leader, while the other ended up a convicted murderer serving a life sentence for a botched jewelry-store robbery.

"The chilling truth is that his story could have been mine. The tragedy is that my story could have been his," Moore writes.

Moore alternates the voices to narrate the stories of both men and, by extension, "a generation of boys trying to find their way in a hostile world."

The book is HERE. 

Don't trust your memory: New study on Dutch soldiers in Afghanistan

It was a dark and stormy night. Suddenly, a shot rang out.

(No, wait. Wrong lead. That was the one we used to play in the newsroom on boring days. We would each start a story with the dark-and-stormy-night lead, and go from there. Let me start again.)

It was New Year's Eve during your deployment in Afghanistan. Suddenly, a missile exploded. Gravel flew. Only through sheer luck was no one injured.

Surreptitiously fed information about this fictional event and then asked about it seven months later, about one out of every four Dutch soldiers in a larger study on PTSD falsely recalled experiencing the missile attack. Individuals with lower intelligence and those who experienced high arousal and more stressors on deployment were more vulnerable to believing misinformation.

It’s yet one more study in a growing body of data suggesting that we should take what people say with an enormous grain of salt -- especially in the contexts in which we forensic professionals often work, involving high-stress events and subjects with cognitive vulnerabilities.

The article, from the European Journal of Psychotraumatology, is available online (without a subscription) HERE.

Dark period in U.S. history: Widespread abuse of mentally ill prisoners documented

It has been an extraordinary three weeks in the history of the American penal system, perhaps one of the darkest periods on record. In four states, from the Atlantic to the Mississippi, from the Gulf of Mexico to the Great Lakes, the systemic abuse and neglect of inmates, and especially mentally ill inmates, has been investigated, chronicled and disclosed in grim detail to the world by lawyers, government investigators and one federal judge. The conclusions are inescapable: In our zeal to dehumanize criminals we have allowed our prisons to become medieval places of unspeakable cruelty so far beyond constitutional norms that they are barely recognizable.

So begins a hard-hitting expose in the Atlantic regarding the U.S. government's refusal to investigate allegations of "grotesque abuses" of mentally ill prisoners in federal penitentiaries, in the wake of similar exposes of conditions in state and local lockups.

The informative article continues HERE.

International violence risk researchers launch free news service

I don't know about you, but I find it incredibly hard to keep up with the burgeoning research in risk assessment. In this era of international fear and carceral control, disciplines from psychology to criminology to nursing to juvenile justice are cranking out more articles each month, and the deluge can feel overwhelming.

Fortunately, two prominent researchers are offering to help us stay organized and up to speed -- for free. The newly created Alliance for International Risk Research (AIRR) will send out a monthly email containing references to all new articles related to forensic risk assessment from over 80 scholarly journals. And all you have to do is sign up.

Jay Singh and Kevin Douglas, AIRR Editors-in-Chief

The AIRR is brought to you by Jay Singh and Kevin Douglas. Dr. Singh, a newly appointed professor and senior researcher for the Department of Justice in Switzerland, is one of the best and brightest around (I've featured his important research on violence risk assessment more than once on this blog); Dr. Douglas is an award-winning psychology professor at Simon Fraser University and co-author of the widely used HCR-20 violence risk assessment tool, among others. 

Their goal is to keep clinicians, policymakers, and researchers up to date in this rapidly evolving field, thus promoting evidence-based practices in the mental health and criminal justice systems. For articles published in languages other than English, the AIRR even boasts an "international coordinator" who will help disseminate the research to a global audience.

Signing up is easy: Just go to THIS LINK and provide your email contract information. The AIRR promises not to bother you with solicitations, survey participation requests or conference announcements -- "simply the latest risk-related research at your fingertips."

Don't delay! The first AIRR bulletin will be arriving in inboxes on Sept. 1.