Archive for the ‘Forensic evidence’ Category
Fact is often stranger than fiction and living here in Texas–we often hear tall tales. Some of them are true while most are pulled out to illustrate a point. Some are colorful and amusing while others take on a life of their own as representative of logical fallacies. Like the Texas sharpshooter tale where you shoot first and later draw the bullseye around the holes left by your bullets. You appear to be a sharpshooter but anyone drawing that conclusion would be sadly mistaken.
The Texas Sharpshooter Fallacy is a variation of what we joked about when I was in graduate school where we referred to this as “drawing the curve before you plot the data”. This logical fallacy is really about making assumptions when you only have partial data or circumstantial evidence. And if you’ve ever watched mock jurors or real jurors–you know this is a common occurrence as trial narratives are presented. If there’s a hole in the story–someone is bound to jump through it.
It’s a funny thing. After almost two decades of doing trial consulting, we know for sure that you can’t always predict how a group of twelve is going to respond to a story. And even when you predict with general accuracy, you don’t always know ‘why’ they would ultimately come to the conclusion they reach. For example, it can be startling how quickly leaps can be made to conspiracy and how persuasive conspiracy theories can be given the right group of jurors.
Whether it’s the Texas sharpshooter fallacy or some other logical fallacy your case narrative elicits–you want to figure out how to plug those gaps in your story and how to identify what sort of person is going to identify a conspiracy where there is none and confuse your other decision makers during deliberation. That conspiracy-prone [“I see a pattern here!”] potential juror is a terrific target for your peremptory strikes. You could even think of pretrial research as shooting bullet holes and then drawing your targets on the jurors who shot them.
Do not pursue a life of crime. And that advice goes beyond the idea you would be too easy to smell. And way beyond the tired recommendation of heavy-duty, clinical strength antiperspirant (although far be it from us to dissuade you from smelling nice). This is instead, as is our tendency here, a recommendation based on research.
Researchers from the Hebrew University of Jerusalem found a way to lift high-quality fingerprints from soaking wet paper. As it turns out, the amino acids in some human sweat can degrade fingerprint quality. In the past, therefore, the sweaty criminal may have been tough to identify. But progress is being made!
“In this study, the scientists fixed this problem by making the gold nanoparticles stick to the paper upon which the fingerprint is located, instead of to the print itself. This method, detailed in the November issue of the German journal Angewandte Chemie [Applied Chemistry], results in a negative image of the fingerprint, with the particles sticking to the divots between the fatty ridges formed by greasy fingers. Since fat is impermeable, the ridges stay in place even when faced with massive amounts of water.“ You can read a detailed description of why this is so tough to do over at the Salamander Hours blog.
It would seem that sweaty criminals have a short time frame for choosing new career paths. So why is this important for litigation advocates to know?
Because it represents a significant advance in finger-printing technology and fingerprint identification.
It is a sign of moving closer to catching criminals whose amino acids may have unwittingly helped them to escape detection up until now.
Plus–there are times when it’s good to know something a little amusing and yet ostensibly relevant for litigation advocacy.
Jaber N, Lesniewski A, Gabizon H, Shenawi S, Mandler D, & Almog J (2012). Visualization of latent fingermarks by nanotechnology: reversed development on paper-a remedy to the variation in sweat composition. Angewandte Chemie (International ed. in English), 51 (49), 12224-7 PMID: 23125068
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The work of the Innocence Project gets a lot of attention. Justifiably so. But did you know that DNA evidence plays no role whatsoever in 90-95% of convictions and therefore, cannot be used to pursue future innocence claims? Pacific Standard has an informative review of non-DNA exonerations that is worth a read.
They talk about EXI–the Exoneration Initiative, a project that takes on cases without DNA evidence in an effort “to exonerate the actually innocent”. Prosecutors work hard to maintain and protect the conviction. As difficult as exonerations are when DNA evidence is available, it is far more difficult without it. Exoneration efforts consume thousands of volunteer work hours and can take years to resolve.
Their cases sometimes hinge on false confessions experts who do are expensive, and who are often not allowed to testify in court. Other times their cases revolve around challenging eyewitness or informant testimony, forensic evidence, the conduct and actions of the arresting or investigating police officers and prosecutors or defense attorneys. As prosecutors and criminal defense attorneys know, once a jury renders a guilty verdict, the accused is now the convict, and all assumptions of innocence cease. The bar is set very high for reversal and exoneration, and achieving this result is exceptionally difficult.
We’ve written about false confessions before and have recommended a non-fiction account by Ray Bonner on wrongful conviction as well as a fictional account from John Grisham. There is nothing entertaining however, in the realities of being imprisoned for a crime you did not commit.
As we’ve listened to mock jurors struggling to comprehend false confessions and why anyone could possibly confess to a heinous crime they did not commit–the hopelessness that is the life of the wrongfully convicted becomes palpable. Even when jurors are told there is no dispute about the person’s innocence–it is hard for them to accept. “Then why was there a confession?” They are appalled at such an extreme miscarriage of justice. But many of them are just as appalled that anyone would falsely confess and thus, they see the false confessor as having significant responsibility for their subsequent conviction and incarceration. Among some, it is easier to blame the victim of false imprisonment than to imagine that the system could go so horribly wrong.
Recently, we listened to mock jurors struggle with a case like this and were surprised to hear reality TV actually educating the mock jurors about the pressures of the interrogation room. Two of the mock jurors watched a show called The First 48 on A&E Television. Evidently, they watched it a lot, and boy did they like it! They were able to describe the “real-life” pressures in the interrogation room and make the idea of a false confession make more sense to the other mock jurors. As one skeptic said, “Well, obviously I know it can happen because I’ve read about DNA exonerations–but it still makes no sense to me that anyone would confess to murder when they didn’t do it. What was wrong with him?” There was no sympathy for the cascade of errors often seen in wrongful conviction cases (e.g., evidence errors, witness errors, police errors, and more) but there was also little sympathy for the man who’d lost his entire young adulthood, both parents and a sibling to his (wrongful) time in prison. “If he had just stood his ground and not confessed, we wouldn’t be here now!”
It’s a nightmare you cannot escape. Kafka comes to mind… Day after day after day. Having advocates like the Innocence Project or the Exoneration Initiative after such a miscarriage of justice is truly a ray of sunlight in a very dark (and typically very, very long) time. Pursuing the evidence needed to free the wrongfully convicted is often a thankless job until an exoneration is granted. That happens more often for the Innocence Project than it does for the Exoneration Initiative–just because of the nature of their focus. We want to thank both of them. They keep showing up after everyone else has gone home.
Or does it? Perhaps not. DNA evidence is powerfully convincing perhaps because “we’ve come to accept the idea that DNA is a sort of individual genetic ‘serial number’ that just needs to be ‘read off’ from a biological sample — but the reality is far more complex”.
Vaughan Bell (who usually writes on the Mind Hacks blog) has an article in the Examiner that alerted us to a study showing how even DNA forensic matching results are often decided in a “judgment call” and not by simply reading off the ‘genetic serial number’. DNA samples obtained at crime scenes may be the DNA of two or more people mixed together. It isn’t simply the victim’s DNA, the perpetrator’s DNA and the roommate’s DNA. It may be all three mixed together. These are called, fairly predictably, “mixed samples”. Vaughan describes the study by Itiel Dror and Greg Hampikian:
In Dror’s study, DNA experts were given results from a mixed sample that was drawn, unknown to them, from a previous real-world case that hinged on whether suspects were present at the scene. After analysing the samples, they not only disagreed with one another but also came to different conclusions depending on whether they had information about the case, or whether they had nothing to go on but the genetic data.
It is worth noting that these findings do not invalidate forensic evidence. Studies also show that despite biases, identification is mostly done reliably, but the fact that outside information can affect decisions remains a worry for the justice system.
Perhaps, not surprisingly, Vaughan’s explanation is much easier to understand than the actual article itself. It’s a good reminder that just like forensic evaluations of legal sanity (or insanity) are somewhat idiosyncratic and reflect the individual examiner’s judgment calls–so, apparently, are the analyses of mixed DNA samples. The story (aka case narrative) needs to make sense without the DNA evidence. Often, what seems to happen, is that the story is tweaked to match the DNA evidence since “DNA doesn’t lie”.
That’s right. DNA doesn’t lie. But it’s clear we don’t yet know exactly how to talk DNAs complex language so we might misinterpret.
If you want to reinforce the credibility of the DNA evidence, refer to it as fact, and frame your trial story with that ‘fact’ as a premise for the other aspects of the story. Jurors are likely to use hindsight bias, based on knowledge of the DNA evidence, to reinforce their views of the non-DNA facets of the story.
Dror IE, & Hampikian G (2011). Subjectivity and bias in forensic DNA mixture interpretation. Science & Justice : Journal of the Forensic Science Society, 51 (4), 204-8 PMID: 22137054
You can trust the results only 55.1% of the time (at least if you are in Hawaii) based on new research examining agreement among forensic evaluators. Hawaii requires multiple and independent evaluations of sanity or insanity in NGRI cases. Agreement is found in a scant majority of cases, and that’s pretty disturbing.
The authors reviewed 483 different evaluation reports which addressed 165 criminal defendants–this represents up to three different forensic psychologists offering independent opinions on a defendant’s legal sanity. There was unanimous agreement (all evaluators concurring on sanity/insanity) only 55.1% of the time. Overall, evaluators recommended sanity in 58.6% of the reports, insanity in 35.4%, and did not offer an opinion in 6% of the cases.
When drugs were involved at the time of the offense, evaluators showed the highest level of disagreement.
When there was a psychotic disorder or when the defendant had been psychiatrically hospitalized shortly prior to the offense, the evaluators agreed more often.
When the cases went to court, the judge sided with the majority opinion among the evaluators 91% of the time. However, when judges disagreed with the majority opinion–they did so to rule the defendant was sane rather than insane.
The researchers in this case recommend additional training. The good news is there was higher agreement when it came to questions of competency to stand trial and evaluations of future dangerousness. Both of those questions as reasons for the evaluations achieved a 68% agreement among the independent forensic evaluators.
In a previous lifetime, I worked in Forensic Rehabilitation with men adjudicated not guilty by reason of insanity (NGRI). I worked in the “Axis I” unit with men who had primarily mood and psychotic disorders. Their stories were very sad and often they had killed loved ones while psychotic. With appropriate medication, many of them were able to return to the community. They were the sad guys.
The “Axis II” unit housed men with primarily character disorders who had received an NGRI decree but whose behavior was determined to be driven by sociopathy, narcissism and psychopathy. They were the bad guys. While some were certainly also experiencing Axis I disorders–a number of them were not (and also not on any medications). Needless to say, there was much more suspicion on the part of rehabilitation staff directed toward the bad guys and more empathy directed at the sad guys.
It’s a real dilemma for the forensic evaluator. If you are not in a combined unit as we were–where those referred for evaluation are observed 24/7 in-house in a residential unit prior to going to trial–you are at the mercy of the documents you have, self-reports and any pre-existing records of behavior. Over time, we tended to believe we knew when mistakes had been made in the evaluation process but many (if not most) evaluators do not have the luxury of long observations of those referred.
As a psychologist, I was asked to testify in court as a treating expert on whether a resident was safe to return to the community. I remember one instance where the prisoner/resident [we'll call him Ted] carried both a psychotic (Axis 1) and a personality disorder (Axis 2) and was heavily medicated. Despite his medications, he continued to hear voices (which were often quite amusing to him). He looked kind of scary–a large, heavily muscled and bald man with tattoos who was also slightly cross-eyed and giggled to himself too much of the time. Not Mr. Rogers.
I knew, after several years of observation and treatment, that he understood his symptoms and that he wouldn’t leave the grounds if he was having what he called “a bad day”. The hearing was just for day passes–which he would use to go to a day treatment program, smoke cigarettes and be off grounds from the facility where he had been under lockdown for a number of years for assault while psychotic.
The prosecutor from the county in which Ted had been tried stood up and said,
“Dr. Handrich–He is obviously still symptomatic and is unable to keep himself from giggling here in the courtroom. How can you say he is not a danger to the community?”
I looked at the prosecutor and then at the judge and grinned. “Well,” I said. “The fact is that we have lots of people in our facility who giggle like that. It isn’t really something we use to assess dangerousness. It’s sort of weird and disconcerting. But it isn’t an indicator of dangerousness.”
That was too much for Ted who bellowed with laughter. The judge coughed and looked away and then agreed. And Ted was fine. If you saw him out there you would probably have a little anxiety based on his intimidating appearance, but Ted didn’t hurt anyone during that trial period and intermittently chose not to leave for the day due to symptom exacerbation.
We had an advantage over the forensic evaluator. We had time. So know that just because an evaluation says someone is legally insane doesn’t mean they really are. And it doesn’t mean they really are not. It’s often a data point in time with little to corroborate or invalidate. It’s the best guess of a professional who has little desire to make a mistake and can only rely on their instruments and experience.
Gowensmith WN, Murrie DC, & Boccaccini MT (2012). How Reliable Are Forensic Evaluations of Legal Sanity? Law and Human Behavior PMID: 22775304