Archive for the ‘Forensic evidence’ Category
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
We all know that neuro-imaging is not ready for courtroom persuasion yet, but did someone remember to tell the jurors? Apparently not–but maybe they already knew.
Are “pictures” of the brain so persuasive that they can sway juror decision making? Even though the credibility of the medical experts has to be factored in, many people believe that when you include brain scan photos (as opposed to bar charts or topographical maps for example) the viewer is more persuaded. Even though there isn’t a chance in the world that an average juror can make sense of the image.
So, the current researchers decided to look at the effect, if any, of neuroimages using a fact pattern of a capital murder case. They were trying to sort out whether it is useful to focus mitigation arguments on neuroimaging evidence, since it could “create the impression the defendant is ‘damaged goods’ and beyond repair.”
The researchers presented the facts of a murder along with evidence (included in nearly all capital trials) of the likelihood of future dangerousness and evidence about the psychiatric condition of the defendant. They divided participants into 3 conditions:
The first group was told the defendant was psychotic.
The second group was told the defendant was psychotic and was given the results of neuropsychological testing discussing damage to the defendant’s brain (specifically, the frontal lobe).
The third group was given the diagnostic information and the test results but also shown color photos of “structural and functional scans of the defendant’s brain” and given descriptions of likely consequences with this sort of damage to the brain.
The researchers expected that the more information participants were given, the less they would choose the death penalty IF the defendant was adjudged to be at low risk for future violence. And they were wrong.
When mock jurors were provided only a diagnosis, and were told the defendant had a high risk of future violence, they were overwhelmingly more likely to give a death sentence (65% voted for death penalty) than other mock jurors. When they were given additional information (either a psychological testing summary or the testing summary with neuroimaging evidence), their imposition of the death sentence dropped dramatically (down to 12% voting for death penalty). If jurors assessing these ‘dangerous’ defendants were given all three forms of information, the death penalty was selected only 8% of the time.
Oddly, low risk of dangerousness only affected those jurors who were only given the diagnosis (but no supportive test data or images). ‘Diagnosis only’ mock jurors assigned the death penalty about 17% of the time (down from 65%), while diagnosis plus testing mock jurors chose the death penalty about 21% of the time and mock jurors receiving all three types of evidence chose the death penalty about 14% of the time (essentially the same as the ‘high risk of violence’ condition).
The researchers concluded that with high risk for future violence defendants, both neuropsychological testing and neuroimaging evidence reduced the likelihood jurors would choose the death penalty. Rather than being ‘aggravating’, this additional evidence was truly mitigating in the case of the high-risk-to-violently-reoffend defendant.
Our view is that this is consistent with what is frequently seen in juror decision-making: Jurors are much more comfortable accepting a high-risk proposition if they are comforted that they have a valid reason for doing it. This is most clearly seen in the high risk group, where they needed to be assured there is ‘scientific evidence’ that the defendant was impaired, not merely that the defense found an expert willing to make that claim. It also suggests that in the population used in the study, there were about 15-20% who were in favor of the death penalty regardless of mitigating scientific evidence.
It’s important to note that the neuropsychological testing results mitigated almost as much as the testing results plus the brain pictures. The verbal description alone (or verbal picture if you will) persuaded jurors. The researchers say it is possible that any additional information pertinent to the defendant’s condition ‘personalizes’ the defendant for jurors and thus may prove mitigating. We go with the former idea, as it seems unlikely that a psychological test profile or a description of neuroimaging studies causes anyone to become more ‘personal’. The jurors simply want reassurance that they are working off more than one person’s opinion.
For the practitioner, this says you don’t need bells and whistles [like brain scans] to successfully mitigate. But you do need solid and scientific information, well-presented using language and examples jurors can understand. That testimony can save a life.
Greene, E., & Cahill, B. (2011). Effects of Neuroimaging Evidence on Mock Juror Decision Making Behavioral Sciences & the Law DOI: 10.1002/bsl.1993
If it’s true, we would then have favorite jeans posthumously. Would that be too cool or simply bizarre? Either way, it may soon be true! Scottish researchers are looking at ways to recover “fingerprint ridge detail and impressions from fabrics”. Doing so has been an elusive goal and the success has come with a technique called vacuum metal deposition (VMD). Basically, gold and zinc is used to recover the fingerprint mark.
Joanna Fraser, a forensic sciences researcher at the University of Abertay, Dundee, said: “The research uses fine layers of metals to display fingerprints people may have left on fabrics, something which is far harder to do with soft surfaces. The technique has been around since the 1970s and is used on many surfaces but was never widely used on fabrics.
“We take these fabrics, place them in a vacuum chamber, then heat up gold to evaporate it and spread a fine film over the fabric. We then heat up zinc, which attaches to the gold where there are no fingerprint residues. This helps reveal the fingerprint — where contact has been made we see the original fabric, where there was no contact we’re left with the grey colour of the metal film.”
She added: “One way of explaining it is like a photographic negative, where colours show up as their opposites. Here the fingerprint ridges show through as clear fabric, but where there are no ridges we see the distinctive grey colour of the metal.
“Previously it had proved difficult to reveal a clear fingerprint on fabric, but we’ve shown that this is now possible. This is great, but the challenge is to develop this further and confirm its effectiveness.”
So, for example, if your favorite jeans had two handprints on the butt—maybe you were shoved off the balcony as opposed to jumping. Or—if scientists find handprints or fingerprints on your favorite jeans—they know to target those areas for further DNA evidence.
There is nothing like a good pair of jeans. Overall, though, I can’t say I’m going to sleep better for knowing this.
Fraser J, Sturrock K, Deacon P, Bleay S, & Bremner DH (2010). Visualisation of fingermarks and grab impressions on fabrics. Part 1: Gold/zinc vacuum metal deposition. Forensic science international PMID: 21126838