Archive for the ‘Science’ Category
Ryan Gabrielson reports in ProPublica:
With the introduction of DNA analysis three decades ago, criminal investigations and prosecutions gained a powerful tool to link suspects to crimes through biological evidence. This field has also exposed scores of wrongful convictions, and raised serious questions about the forensic science used in building cases.
This week, The Washington Post reported the first results from a sweeping study of the FBI forensic hair comparison unit, finding that 26 of 28 examiners in the unit gave flawed testimony in more than 200 cases during the 1980s and 1990s. Examiners overstated the accuracy of their analysis in ways that aided prosecutors. The National Association of Criminal Defense Lawyers and the Innocence Project are conducting the study with the cooperation of the U.S. Justice Department.
The development is only the latest to shake public faith in what police and prosecutors have often cited as scientific proof. In 2009, the National Academy of Sciences published an exhaustive review of the forensic sciences, concluding that only nuclear DNA analysis has a foundation in research. “Although research has been done in some disciplines,” the report states, “there is a notable dearth of peer-reviewed, published studies establishing the scientific bases and validity of many forensic methods.”
Fields based on matching patterns in fingerprints and hair have unknown error rates. Other methods are believed to be even more dubious, most notably the analysis of bite-mark injuries on victims’ bodies. Still, while the forensic sciences are under scrutiny, unproven practices, both old and new, continue to be used in courtrooms.
We’ve gathered some of the best reporting on questionable forensic science and evidence. Have we missed any? Please let us know in the comments below.
Convicted defendants left uninformed of forensic flaws found by Justice Dept
The Washington Post, April 2012
The Post story that spurred study of the FBI hair matching unit, which details how justice department officials failed to respond to widespread concerns about its fiber analysis. The FBI withheld the information from convicts whose cases included testimony from the troubled lab. “As a result, hundreds of defendants nationwide remain in prison or on parole for crimes that might merit exoneration, a retrial or a retesting of evidence using DNA because FBI hair and fiber experts may have misidentified them as suspects,” Spencer S. Hsu wrote.
Trial By Fire
The New Yorker, September 2009
The story of Cameron Todd Willingham, convicted of setting the fire that destroyed his Texas home and killed his one-year-old twin daughters. Willingham’s conviction rested on investigators’ belief that burn patterns proved the young father had poured a liquid accelerant to propel the blaze. Researchers would prove that theory baseless. The discovery did not benefit Willingham, who had been executed in 2004.
The Bite-Marks Men
Slate, February 2008
Two men in Mississippi were wrongly convicted for the rapes and murders of young girls based on bite-mark analysis by Dr. Michael West, a longtime expert witness in the state’s criminal courts. The entire method of analyzing bite marks is in question.
Texas Monthly, May 2010
Deputy Keith Pikett with the Fort Bend County Sheriff’s Office, outside Houston, connected people to crime scenes through “scent” lineups for his police dogs across Texas. Pikett would expose his dogs to a smell from the scene, and then have them sniff scent samples from the suspect and a series of uninvolved people. Pikett would testify dogs’ “body language” alerted him of alleged matches, helping to indict more than 1,000 suspects using the dubious technique.
Playing With Fire
The Intercept, February 2015
Another case in which fire investigators followed burn patterns to an incorrect conclusion, and a conviction. In 1992, Lorie Lee Lance died of smoke inhalation, crouched on the floor of a utility room as her home in Tennessee burned. Police suspected Lance’s boyfriend, Claude Garrett, had locked her in the room and set the blaze. However, the investigation had found the door was unlocked.
The Hardest Cases: When Children Die, Justice Can Be Elusive
ProPublica, June 2011 . . .
Continue reading. There are more at the link.
Jordan Smith reports in The Intercept:
Last week, the Washington Post revealed that, in 268 trials dating back to 1972, 26 out of 28 examiners within the FBI Laboratory’s microscopic hair comparison unit “overstated forensic matches in a way that favored prosecutors in more than 95 percent” of the cases. These included cases where 14 people have since been either executed or died in prison.
The hair analysis review — the largest-ever post-conviction review of questionable forensic evidence by the FBI— has been ongoing since 2012. The review is a joint effort by the FBI, Innocence Project and the National Association of Criminal Defense Lawyers. The preliminary results announced last week represent just a small percentage of the nearly 3,000 criminal cases in which the FBI hair examiners may have provided analysis. Of the 329 DNA exonerations to date, 74 involved flawed hair evidence analysis.
While these revelations are certainly disturbing – and the implications alarming – the reality is that they represent the tip of the iceberg when it comes to flawed forensics.
In a landmark 2009 report, the National Academy of Sciences concluded that, aside from DNA, there was little, if any, meaningful scientific underpinning to many of the forensic disciplines. “With the exception of nuclear DNA analysis…no forensic method has been rigorously shown to have the capacity to consistently, and with a high degree of certainty, demonstrate a connection between evidence and a specific individual or source,” reads the report.
There is one thing that all troubling forensic techniques have in common: They’re all based on the idea that patterns, or impressions, are unique and can be matched to the thing, or person, who made them. But the validity of this premise has not been subjected to rigorous scientific inquiry. “The forensic science community has had little opportunity to pursue or become proficient in the research that is needed to support what it does,” the NAS report said.
Nonetheless, courts routinely allow forensic practitioners to testify in front of jurors, anointing them “experts” in these pattern-matching fields – together dubbed forensic “sciences” despite the lack of evidence to support that – based only on their individual, practical experience. These witnesses, who are largely presented as learned and unbiased arbiters of truth, can hold great sway with jurors whose expectations are often that real life mimics the television crime lab or police procedural.
But that is not the case, as the first results from the FBI hair evidence review clearly show. And given the conclusions of the NAS report, future results are not likely to improve. What’s more, if other pattern-matching disciplines were subjected to the same scrutiny as hair analysis, there is no reason to think the results would be any better. For some disciplines the results could even be worse. Consider the examples below:
1. Bite-mark analysis is based on two falsehoods and wrongfully convicted at least 24 people
“Hair comparison analysis is practically DNA compared to bite mark analysis,” says Chris Fabricant, director of strategic litigation for the Innocence Project. Bite mark analysis – generally the practice of identifying alleged bite marks on human skin and then matching the pattern left behind to a person’s dentition – relies on two basic assumptions: One, that human dentition, like DNA, is unique; and, two, that human skin is a good medium for transferring, and preserving, a bite mark impression. But as it turns out, neither is true, according to research conducted by Mary Bush, a professor of dentistry at the State University of New York at Buffalo, who, with her team has conducted the only actual scientific inquiries into the practice in decades.
Indeed, some of the harshest criticism contained in the NAS report focuses on bite-mark evidence, and concludes that there is no scientific underpinning to the discipline. In a recent four-part series on bite-mark analysis, the Washington Post’s Radley Balko described how forensic odontologists – dentists who profess expertise in bite mark analysis (and who are qualified as such by the American Board of Forensic Odontology) not only reject the NAS’s conslusion, but actively attack anyone who dares to criticize the field. Two examples: In 2013, ABFO leadership orchestrated an aggressive – and ultimately unsuccessful – plan to expel their own colleague, Dr. Michael Bowers, from membership within the American Academy of Forensic Sciences, which would have hamstrung Bowers from testifying against the practice in court. His crime: being a vocal critic of bite mark “science.” In 2014, speaking at an ABFO dinner, Manhattan prosecutor Melissa Mourges, a strident supporter of bite mark evidence, not only derided Mary Bush’s work, but also peppered her remarks with petty insults about Bush’s physical appearance.
Of course, as it is with hair analysis — and, really, any of the questionable forensic disciplines critiqued by the NAS — the utter lack of a scientific foundation has done nothing to keep bite mark evidence out of the courtroom. To date, DNA has exonerated 24 individuals sent to prison on bite mark evidence.
2. Dexter lied to you about blood spatters. They sow chaos and confusion.
In the popular Showtime series Dexter, serial killer of serial killers Dexter Morgan has a day job with the Miami police, where he works as a blood-spatter analyst. The episodes show him expertly analyzing sprays of blood on walls or drops on floors, quickly – and reliably – arriving at a concrete theory of the crime that, more often than not, leads the PD’s homicide detectives to swift resolution.
If only it were that easy.
While there is some actual science involved in bloodstain-pattern analysis — knowledge of the physics of fluids is helpful, as is an understanding of the pathology of wounds — the sheer number of variables involved in the creation of any given bloodstain makes reaching any definitive conclusion about the circumstances of its origin difficult at best. “The uncertainties associated with bloodstain pattern analysis are enormous,” the NAS report concluded.
Yet for defendants, as with other forensic disciplines, the conclusions of a bloodstain “expert,” can mean the difference between living free or behind bars. The NAS report warns that while science supports “some aspects” of bloodstain pattern analysis —whether blood “spattered quickly or slowly” for example — some experts “extrapolate far beyond what can be concluded.” This risk was powerfully demonstrated in the bizarre case of Warren Horinek, a former Ft. Worth, Texas police officer who, based solely on the conclusions of a blood pattern expert, was convicted and sentenced to 30 years in prison for the 1995 murder of his wife — a death that the police, medical examiner, and prosecutor all concluded was actually suicide.
Horinek remains in prison.
3. Worn shoes and tires can land you on death row, but there’s no evidence they’re unique . . .
Watch this earthflow in western Russia that occurred on 1 April 2015—and I don’t believe it’s an April Fool’s joke:
Apparently it’s a mine-waste failure. The US has had several bad failures regarding mine waste, but nothing on this scale, so far as I know. Yet.
Quite a collection of stunning photos. Take a look. Here’s just one, the Pillars of Creation in the Eagle Nebula:
Intelligence comes in a variety of flavors, it seems. Joshua Foer reports on research trying to understand dolphin communication and intelligence:
Head trainer Teri Turner Bolton looks out at two young adult male dolphins, Hector and Han, whose beaks, or rostra, are poking above the water as they eagerly await a command. The bottlenose dolphins at the Roatán Institute for Marine Sciences (RIMS), a resort and research institution on an island off the coast of Honduras, are old pros at dolphin performance art. They’ve been trained to corkscrew through the air on command, skate backward across the surface of the water while standing upright on their tails, and wave their pectoral fins at the tourists who arrive several times a week on cruise ships.
But the scientists at RIMS are more interested in how the dolphins think than in what they can do. When given the hand signal to “innovate,” Hector and Han know to dip below the surface and blow a bubble, or vault out of the water, or dive down to the ocean floor, or perform any of the dozen or so other maneuvers in their repertoire—but not to repeat anything they’ve already done during that session. Incredibly, they usually understand that they’re supposed to keep trying some new behavior each session.
Bolton presses her palms together over her head, the signal to innovate, and then puts her fists together, the sign for “tandem.” With those two gestures, she has instructed the dolphins to show her a behavior she hasn’t seen during this session and to do it in unison.
Hector and Han disappear beneath the surface. With them is a comparative psychologist named Stan Kuczaj, wearing a wet suit and snorkel gear and carrying a large underwater video camera with hydrophones. He records several seconds of audible chirping between Hector and Han, then his camera captures them both slowly rolling over in unison and flapping their tails three times simultaneously.
Above the surface Bolton presses her thumbs and middle fingers together, telling the dolphins to keep up this cooperative innovation. And they do. The 400-pound animals sink down, exchange a few more high-pitched whistles, and then simultaneously blow bubbles together. Then they pirouette side by side. Then they tail walk. After eight nearly perfectly synchronized sequences, the session ends.
There are two possible explanations of this remarkable behavior. Either one dolphin is mimicking the other so quickly and precisely that the apparent coordination is only an illusion. Or it’s not an illusion at all: When they whistle back and forth beneath the surface, they’re literally discussing a plan.
When a chimpanzee gazes at a piece of fruit or a silverback gorilla beats his chest to warn off an approaching male, it’s hard not to see a bit of ourselves in those behaviors and even to imagine what the animals might be thinking. We are, after all, great apes like them, and their intelligence often feels like a diminished—or at least a familiar—version of our own. But dolphins are something truly different. They “see” with sonar and do so with such phenomenal precision that they can tell from a hundred feet away whether an object is made of metal, plastic, or wood. They can even eavesdrop on the echolocating clicks of other dolphins to figure out what they’re looking at. Unlike primates, they don’t breathe automatically, and they seem to sleep with only half their brains resting at a time. Their eyes operate independently of each other. They’re a kind of alien intelligence sharing our planet—watching them may be the closest we’ll come to encountering ET.
Dolphins are extraordinarily garrulous. Not only do they whistle and click, but they also emit loud broadband packets of sound called burst pulses to discipline their young and chase away sharks. Scientists listening to all these sounds have long wondered what, if anything, they might mean. Surely such a large-brained, highly social creature wouldn’t waste all that energy babbling beneath the waves unless the vocalizations contained some sort of meaningful content. And yet despite a half century of study, nobody can say what the fundamental units of dolphin vocalization are or how those units get assembled.
“If we can find a pattern connecting vocalization to behavior, it’ll be a huge deal,” says Kuczaj, 64, who has published more scientific articles on dolphin cognition than almost anyone else in the field. He believes that his work with the synchronized dolphins at RIMS may prove to be a Rosetta stone that unlocks dolphin communication, though he adds, “The sophistication of dolphins that makes them so interesting also makes them really difficult to study.”
Yet virtually no evidence supports the existence of anything resembling a dolphin language, and some scientists express exasperation at the continued quixotic search. “There is also no evidence that dolphins cannot time travel, cannot bend spoons with their minds, and cannot shoot lasers out of their blowholes,” writes Justin Gregg, author of Are Dolphins Really Smart? The Mammal Behind the Myth. “The ever-present scientific caveat that ‘there is much we do not know’ has allowed dolphinese proponents to slip the idea of dolphin language in the back door.”
But where Gregg sees a half century of failure, Kuczaj and other prominent researchers see a preponderance of circumstantial evidence that leads them to believe that the problem simply hasn’t yet been looked at in the right way, with the right set of tools. It’s only within the past decade or so that high-frequency underwater audio recorders, like the one Kuczaj uses, have been able to capture the full spectrum of dolphin sounds, and only during the past couple of years that new data-mining algorithms have made possible a meaningful analysis of those recordings. Ultimately dolphin vocalization is either one of the greatest unsolved mysteries of science or one of its greatest blind alleys.
Until our upstart genus surpassed them, dolphins were probably the largest brained, and presumably the most intelligent, creatures on the planet. Pound for pound, relative to body size, their brains are still among the largest in the animal kingdom—and larger than those of chimpanzees. The last common ancestor of humans and chimps lived some six million years ago. By comparison cetaceans such as dolphins split off from the rest of the mammal lineage about 55 million years ago, and they and primates haven’t shared an ancestor for 95 million years.
This means that primates and cetaceans have been on two different evolutionary trajectories for a very long time, and the result is not only two different body types but also two different kinds of brains. Primates, for example, have large frontal lobes, which are responsible for executive decision-making and planning. Dolphins don’t have much in the way of frontal lobes, but they still have an impressive flair for solving problems and, apparently, a capacity to plan for the future. We primates process visual information in the back of our brains and language and auditory information in the temporal lobes, located on the brain’s flanks. Dolphins process visual and auditory information in different parts of the neocortex, and the paths that information takes to get into and out of the cortex are markedly different. Dolphins also have an extremely well developed and defined paralimbic system for processing emotions. One hypothesis is that it may be essential to the intimate social and emotional bonds that exist within dolphin communities.
“A dolphin alone is not really a dolphin,” says Lori Marino, a biopsychologist and executive director of the Kimmela Center for Animal Advocacy. “Being a dolphin means being embedded in a complex social network. Even more so than with humans.”
When dolphins are in trouble, they display a degree of cohesiveness rarely seen in other animal groups. If one becomes sick and heads toward shallow water, the entire group will sometimes follow, which can lead to mass strandings. It’s as if they have a singular focus on the stranded dolphin, Marino says, “and the only way to break that concentration may be to give them something equally strong to pull them away.” A mass stranding in Australia in 2013 was averted only when humans intervened, capturing a juvenile of the group and taking her out to the open ocean; her distress calls drew the group back to sea. . .
Perhaps the FBI relies so heavily on informants (whom the FBI often pays to precipitate plots that the FBI can then “discover” and “prevent”) because the FBI forensics are so poorly done. Spence Hsu reports in the Washington Post:
The Justice Department and FBI have formally acknowledged that nearly every examiner in an elite FBI forensic unit gave flawed testimony in almost all trials in which they offered evidence against criminal defendants over more than a two-decade period before 2000.
Of 28 examiners with the FBI Laboratory’s microscopic hair comparison unit, 26 overstated forensic matches in ways that favored prosecutors in more than 95 percent of the 268 trials reviewed so far, according to the National Association of Criminal Defense Lawyers (NACDL) and the Innocence Project, which are assisting the government with the country’slargest post-conviction review of questioned forensic evidence.
The cases include those of 32 defendants sentenced to death. Of those, 14 have been executed or died in prison, the groups said under an agreement with the government to release results after the review of the first 200 convictions.
The FBI errors alone do not mean there was not other evidence of a convict’s guilt. Defendants and federal and state prosecutors in 46 states and the District are being notified to determine whether there are grounds for appeals. Four defendants were previously exonerated.
The admissions mark a watershed in one of the country’s largest forensic scandals, highlighting the failure of the nation’s courts for decades to keep bogus scientific information from juries, legal analysts said. The question now, they said, is how state authorities and the courts will respond to findings that confirm long-suspected problems with subjective, pattern-based forensic techniques — like hair and bite-mark comparisons — that have contributed to wrongful convictions in more than one-quarter of 329 DNA-exoneration cases since 1989.
In a statement, the FBI and Justice Department vowed to continue to devote resources to address all cases and said they “are committed to ensuring that affected defendants are notified of past errors and that justice is done in every instance. The Department and the FBI are also committed to ensuring the accuracy of future hair analysis testimony, as well as the application of all disciplines of forensic science.”
Peter Neufeld, co-founder of the Innocence Project, commended the FBI and department for the collaboration but said, “The FBI’s three-decade use of microscopic hair analysis to incriminate defendants was a complete disaster.”
“We need an exhaustive investigation that looks at how the FBI, state governments that relied on examiners trained by the FBI and the courts allowed this to happen and why it wasn’t stopped much sooner,” Neufeld said.
Norman L. Reimer, the NACDL’s executive director, said, “Hopefully, this project establishes a precedent so that in future situations it will not take years to remediate the injustice.”
While unnamed federal officials previously acknowledged widespreadproblems, the FBI until now has withheld comment because findings might not be representative. . .
It’s a long article and worth reading in its entirety. Later in the article:
University of Virginia law professor Brandon L. Garrett said the results reveal a “mass disaster” inside the criminal justice system, one that it has been unable to self-correct because courts rely on outdated precedents admitting scientifically invalid testimony at trial and, under the legal doctrine of finality, make it difficult for convicts to challenge old evidence.
“The tools don’t exist to handle systematic errors in our criminal justice system,” Garrett said. “The FBI deserves every recognition for doing something really remarkable here. The problem is there may be few judges, prosecutors or defense lawyers who are able or willing to do anything about it.”
And also, ominously:
Also, the same FBI examiners whose work is under review taught 500 to 1,000 state and local crime lab analysts to testify in the same ways.
UPDATE: Eric Lander writes in the NY Times on the same topic:
THE F.B.I. stunned the legal community on Monday with its acknowledgment that testimony by its forensic scientists about hair identification was scientifically indefensible in nearly every one of more than 250 cases reviewed. But the conclusion should come as no surprise to scientists. It is the culmination of a collision between law and science that began in 1989 in a Bronx courtroom with the murder trial of a janitor.
The case was the first to carefully evaluate the use of DNA fingerprinting. As a geneticist, I served pro bono as an expert witness for the defense. While prosecutors were dazzled by the potential of DNA technology to pinpoint perpetrators, the testing lab’s work proved to be shoddy and its conclusions unreliable. In a rare move, the scientific experts for both the prosecution and defense met and unanimously declared the DNA evidence unacceptable. The trial judge had little choice but to agree.
Shaken by the ruling, the National Academy of Sciences and the F.B.I. moved in the early 1990s to establish rigorous methods for DNA fingerprinting, which soon became the gold standard for forensics. The lawyers in the Bronx case, Barry Scheck and Peter Neufeld, went on to start the Innocence Project, which has used DNA as an objective lens to scrutinize past convictions. Such efforts have led to the exoneration or release of more than 300 people, including 20 who served time on death row.
As miscarriages of justice piled up, it became essential to understand precisely how the criminal justice system made such mistakes and how to prevent them. Troublingly, about a quarter of the cases examined by the Innocence Project (on whose board I now serve) involved forensic scientists who had erroneously claimed to identify defendants with near-certainty by matching hair samples, fibers, shoe prints or bite marks.
There were clearly fundamental problems with forensic science. A 2009 report by the National Research Council, an arm of the National Academies, found that apart from DNA testing, no forensic method had been rigorously shown to consistently and reliably demonstrate a connection between evidence and a specific person.
Then, several years ago, three men from the Washington area — Kirk Odom, Santae Tribble and Donald Gates — were exonerated in separate cases. They had served more than 70 years in prison in total. In each case, F.B.I. examiners had told juries that the defendant’s hair matched hair at the crime scene, based on microscopic hair analysis. One prosecutor put the odds at perhaps one in 10 million that the hairs belonged to someone other than the defendant. (In fact, subsequent DNA testing found that none of the hair samples matched the defendant, and that one was from a dog.)
Those cases proved to be a turning point. To its credit, the Justice Department reached an agreement with the Innocence Project to review F.B.I. testimony about hair analysis in more than 2,500 cases in more than 40 states from 1985 to 1999. The results of the first 268 cases examined were reported Sunday in The Washington Post. The review found that F.B.I. testimony was fundamentally flawed in 257 of those cases — a stunning 96 percent of the total. Of those defendants, 33 received the death penalty and nine have been executed so far. Although the errors don’t necessarily mean the defendants are innocent — other evidence might have supported conviction — the F.B.I. plans to notify prosecutors and prisoners of the findings.
The problem is not limited to hair analysis. Last month, Alabama released a man from death row who had been convicted 30 years ago based solely on ballistics evidence; the state now concedes that the bullets in question did not actually match the weapon used. A few years earlier, Mississippi released two men who had been convicted of separate murders based on testimony that their teeth perfectly matched bite marks on the victims. After the true killer was later identified by DNA, experts concluded the wounds were not human bites after all but were most likely caused by crawfish and insects nibbling on the corpses. . .
See also the exchange of views under the heading, “Judging Forensic Science.”