Tag Archives: Criminal Law

University of Melbourne and Aalborg University study: How convincing is a Y-chromosome profile match between suspect and crime scene? Study aims to improve the validity and intelligibility of Y-chromosome evidence presented in court

4 Nov

Sarah C. P. Williams wrote in the Science article, Y Chromosome Is More Than a Sex Switch:

The small, stumpy Y chromosome—possessed by male mammals but not females, and often shrugged off as doing little more than determining the sex of a developing fetus—may impact human biology in a big way. Two independent studies have concluded that the sex chromosome, which shrank millions of years ago, retains the handful of genes that it does not by chance, but because they are key to our survival. The findings may also explain differences in disease susceptibility between men and women.
“The old textbook description says that once maleness is determined by a few Y chromosome genes and you have gonads, all other sex differences stem from there,” says geneticist Andrew Clark of Cornell University, who was not involved in either study. “These papers open up the door to a much richer and more complex way to think about the Y chromosome….” http://www.sciencemag.org/news/2014/04/y-chromosome-more-sex-switch

See, National Institute of Standards and Technology study: Courtroom use of ‘Likelihood Ratio’ not consistently supported by scientific reasoning approach https://wordpress.com/posts/drwilda.com and More Innocent People on Death Row Than Estimated: Study http://time.com/79572/more-innocent-people-on-death-row-than-estimated-study/

Science Daily reported in How convincing is a Y-chromosome profile match between suspect and crime scene?

David Balding of the University of Melbourne, Australia and Mikkel Andersen of Aalborg University in Denmark have developed new, open-source software that can help understand how many people in a population will match a single Y-chromosome profile detected at a crime scene, which they describe in a new study in PLOS Genetics.
Forensic analysis of Y-chromosome DNA is especially useful when a small amount of male DNA is mixed in with a large amount of female DNA, such as occurs in sexual assault cases. Explaining this evidence in court, however, is difficult because the Y chromosome passes down mostly unchanged from fathers to sons, so a single Y-chromosome profile can be shared by dozens of men in a population.
Instead of a match probability or database count, Balding and Andersen propose that courts be told about the likely number of matching males in the population, and the possible consequences of their relatedness, which is often more distant than uncle or cousin but much closer than for a random man. They also show how the distribution of matching males can be affected by database information, and suggest ways to present this information in court to make clear that Y-chromosome evidence cannot definitively identify the culprit, but can dramatically reduce the number of possible sources of the DNA. The court must then decide if it has enough other evidence to identify the suspect as the source of the Y-chromosome profile, rather than one of his matching (distant) relatives.
After the introduction of DNA profiling using non-sex chromosomes, the procedure had problems that, once addressed, made profiling a powerful tool that has revolutionized forensic science. Now, Y chromosome profiling must undergo the same process to quantify the results in a way that is valid and directly interpretable to courts. The new software presented in this study could be used to improve the accuracy of Y chromosome evidence and to increase its understanding by judges and jurors…. https://www.sciencedaily.com/releases/2017/11/171103142725.htm

Citation:

How convincing is a Y-chromosome profile match between suspect and crime scene?
Study aims to improve the validity and intelligibility of Y-chromosome evidence presented in court
Date: November 3, 2017
Source: PLOS
Summary:
Scientists have developed new, open-source software that can help understand how many people in a population will match a single Y-chromosome profile detected at a crime scene.
Journal Reference:
1. Mikkel M. Andersen, David J. Balding. How convincing is a matching Y-chromosome profile? PLOS Genetics, 2017; 13 (11): e1007028 DOI: 10.1371/journal.pgen.1007028

Here is the press release:

Public Release: 3-Nov-2017
How convincing is a Y-chromosome profile match between suspect and crime scene?
Study aims to improve the validity and intelligibility of Y-chromosome evidence presented in court
PLOS
David Balding of the University of Melbourne, Australia and Mikkel Andersen of Aalborg University in Denmark have developed new, open-source software that can help understand how many people in a population will match a single Y-chromosome profile detected at a crime scene, which they describe in a new study in PLOS Genetics.
Forensic analysis of Y-chromosome DNA is especially useful when a small amount of male DNA is mixed in with a large amount of female DNA, such as occurs in sexual assault cases. Explaining this evidence in court, however, is difficult because the Y chromosome passes down mostly unchanged from fathers to sons, so a single Y-chromosome profile can be shared by dozens of men in a population.
Instead of a match probability or database count, Balding and Andersen propose that courts be told about the likely number of matching males in the population, and the possible consequences of their relatedness, which is often more distant than uncle or cousin but much closer than for a random man. They also show how the distribution of matching males can be affected by database information, and suggest ways to present this information in court to make clear that Y-chromosome evidence cannot definitively identify the culprit, but can dramatically reduce the number of possible sources of the DNA. The court must then decide if it has enough other evidence to identify the suspect as the source of the Y-chromosome profile, rather than one of his matching (distant) relatives.
After the introduction of DNA profiling using non-sex chromosomes, the procedure had problems that, once addressed, made profiling a powerful tool that has revolutionized forensic science. Now, Y chromosome profiling must undergo the same process to quantify the results in a way that is valid and directly interpretable to courts. The new software presented in this study could be used to improve the accuracy of Y chromosome evidence and to increase its understanding by judges and jurors.
David Balding adds: “We think this work is going to make a big improvement to how Y profile evidence is presented in courts. We will soon extend this work to mixtures of Y-chromosome profiles from multiple males, and also address the corresponding problem for the maternally-inherited mtDNA profiles. Our approach also allows us to include information from any relatives of the suspect whose profile is already available, and we will be working to develop that aspect.”
###
In your coverage please use this URL to provide access to the freely available article in PLOS Genetics:
http://journals.plos.org/plosgenetics/article?id=10.1371/journal.pgen.1007028
Citation: Andersen MM, Balding DJ (2017) How convincing is a matching Y-chromosome profile? PLoS Genet 13(11): e1007028. https://doi.org/10.1371/journal.pgen.1007028
Image Credit: Mikkel Andersen
Image Caption: A simplified illustration of a simulated population of males, with lines indicating father-son links. The suspected source of the DNA, whose profile matches that from the crime scene, is shown in red and other males with matching Y profiles, who are often close relatives, are yellow. The dashed line separates the last three generations, those further back in time will typically be already dead or otherwise unlikely to be of interest (depending on the circumstances of the crime).
Funding: The authors wish to thank the Isaac Newton Institute for Mathematical Sciences, Cambridge UK, for support and hospitality during the programme Probability and Statistics in Forensic Science, where this paper was conceived. The programme was supported by EPSRC grant no EP/K032208/1. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Competing Interests: The authors have declared that no competing interests exist.
Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system. https://www.eurekalert.org/pub_releases/2017-11/p-hci103117.php

Mathew Shaer wrote in the The False Promise of DNA Testing: The forensic technique is becoming ever more common—and ever less reliable.:

Modern forensic science is in the midst of a great reckoning. Since a series of high-profile legal challenges in the 1990s increased scrutiny of forensic evidence, a range of long-standing crime-lab methods have been deflated or outright debunked. Bite-mark analysis—a kind of dental fingerprinting that dates back to the Salem witch trials—is now widely considered unreliable; the “uniqueness and reproducibility” of ballistics testing has been called into question by the National Research Council. In 2004, the FBI was forced to issue an apology after it incorrectly connected an Oregon attorney named Brandon Mayfield to that spring’s train bombings in Madrid, on the basis of a “100 percent” match to partial fingerprints found on plastic bags containing detonator devices. Last year, the bureau admitted that it had reviewed testimony by its microscopic-hair-comparison analysts and found errors in at least 90 percent of the cases. A thorough investigation is now under way…. https://www.theatlantic.com/magazine/archive/2016/06/a-reasonable-doubt/480747/

The reliability of the evidence and the ability of a particular accused to defend against evidence presented in a court hearing is crucial to preventing the innocent from being convicted.

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Canisius College study: Bite-mark analysis can lead to false convictions

11 Jan

Erik Eckholm wrote in the New York Times article, Mississippi Death Row Case Faults Bite-Mark Forensics:

In one of the country’s first nationally televised criminal trials, of the smirking serial murderer Ted Bundy in Florida in 1979, jurors and viewers alike were transfixed as dental experts showed how Mr. Bundy’s crooked teeth resembled a bite on a 20-year-old victim.

Mr. Bundy was found guilty and the obscure field of “forensic dentistry” won a place in the public imagination.

Since then, expert testimony matching body wounds with the dentition of the accused has played a role in hundreds of murder and rape cases, sometimes helping to put defendants on death row.

But over this same period, mounting evidence has shown that matching body wounds to a suspect’s dentition is prone to bias and unreliable.

A disputed bite-mark identification is at the center of an appeal that was filed Monday with the Mississippi Supreme Court. Eddie Lee Howard Jr., 61, has been on death row for two decades for the murder and rape of an 84-year-old woman, convicted largely because of what many experts call a far-fetched match of his teeth to purported bite wounds, discerned only after the woman’s body had been buried and exhumed.

The identification was made by Dr. Michael West, a Mississippi dentist who was sought out by prosecutors across the country in the 1980s and 1990s but whose freewheeling methods “put a huge black eye on bite-mark evidence,” in the words of Dr. Richard Souviron, a Florida-based dental expert who helped identify Mr. Bundy in 1979, in an interview last week.

Since 2000, at least 17 people convicted of murder or rape based on “expert” bite matches have been exonerated and freed, usually because DNA tests showed they had been wrongfully accused, according to research by the Innocence Project in New York. Dr. West was the expert witness in two of those cases.

In six additional cases, one involving Dr. West and one involving Dr. Souviron, indictments and arrests linked to bite-mark identifications were dropped after new evidence showed that the matches were wrong….http://www.nytimes.com/2014/09/16/us/mississippi-death-row-appeal-highlights-shortcomings-of-bite-mark-identifications.html?_r=0

A Canisius College study throws further doubt on the legitimacy of Bite-mark analysis.

Science Daily reported in Bite-mark analysis can lead to false convictions, landmark research shows:

Forensic science is a vital crime-fighting tool in today’s criminal justice system. But it can also lead to false convictions, according to H. David Sheets, PhD. Landmark research by the Canisius College physics professor proves that bite-mark analysis is “far from an exact science.”

Bite-mark analysis compares the teeth of crime suspects to bite-mark patterns on victims. Historically, forensic odontologists (dentists who provide forensic dental identifications in criminal investigations and mass disasters) operate under two general guidelines when interpreting bite-mark evidence. First, that everyone’s dental impression is unique to the individual, “similar to fingerprints,” Sheets explains. Second, that human skin — the most common material on which a bite mark is inflicted — reliably records an individual’s dental impression.

Bite-mark analysis is widely accepted in criminal courts and often presented as key evidence in prosecutions. “People assume that it’s close to fingerprints in terms of accuracy,” Sheets says. “But the notions that a person’s dentition is unique or that the human skin can accurately record an individual’s bite mark have never been validated scientifically.”

Sheets and his colleagues, Mary A. Bush, DDS and Peter J. Bush, from the University at Buffalo (UB) School of Dental Medicine, sought to do just that.

Using a variety of dental impressions, they examined more than 1,000 human dentitions and studied hundreds of bite marks in cadaver skin. With the help of computer analysis and applied statistics, the team then worked to match its database of bite marks to the correct dental impressions.

“When the dental alignments were similar, it was difficult to distinguish exactly which set of teeth made which bites,” Sheets says. “That tells us that a single bite mark is not distinct enough to be linked to a specific individual. It can actually point to many different individuals.” This means that a false identification is possible, which can lead a police investigation away from the real perpetrator and toward an innocent individual.

The Canisius-UB studies are among the largest conducted on bite-mark analysis and the first to use human-skin models (rather than animal models, wax or Styrofoam). More notable is that its findings call into question criminal convictions that rested entirely on bite-mark evidence.

Since 2000, at least 25 people convicted on bite-mark evidence have been exonerated due to advances in DNA testing, according to the Innocence Project. The national organization, which works to free wrongfully convicted individuals, is now using the Canisius-UB studies to help build a case for having bite-mark evidence cast out of criminal proceedings.

“This is an example of where science can help prevent future wrongful convictions and perhaps even provide some social justice to those already convicted,” Sheets concludes….                                   http://www.sciencedaily.com/releases/2016/01/160108134949.htm

Citation:

Bite-mark analysis can lead to false convictions, landmark research shows

Date:         January 8, 2016

Source:     Canisius College

Summary:

Forensic science is a vital crime-fighting tool in today’s criminal justice system. But it can also lead to false convictions, according to an expert, whose study proves that bite-mark analysis is “far from an exact science.”

Here is the press release from Canisius College:

Landmark Research Shows Bite-Mark Analysis Can Lead to False Convictions

Findings call into question criminal convictions that rested entirely on bite-mark evidence.

Released: 8-Jan-2016 9:05 AM EST
Source Newsroom: Canisius College

Newswise — Forensic science is a vital crime-fighting tool in today’s criminal justice system. But it can also lead to false convictions, according to H. David Sheets, PhD. Landmark research by the Canisius College physics professor proves that bite-mark analysis is “far from an exact science.”

Bite-mark analysis compares the teeth of crime suspects to bite-mark patterns on victims. Historically, forensic odontologists (dentists who provide forensic dental identifications in criminal investigations and mass disasters) operate under two general guidelines when interpreting bite-mark evidence. First, that everyone’s dental impression is unique to the individual, “similar to fingerprints,” Sheets explains. Second, that human skin – the most common material on which a bite mark is inflicted – reliably records an individual’s dental impression.

Bite-mark analysis is widely accepted in criminal courts and often presented as key evidence in prosecutions. “People assume that it’s close to fingerprints in terms of accuracy,” Sheets says. “But the notions that a person’s dentition is unique or that the human skin can accurately record an individual’s bite mark have never been validated scientifically.”

Sheets and his colleagues, Mary A. Bush, DDS and Peter J. Bush, from the University at Buffalo (UB) School of Dental Medicine, sought to do just that.

Using a variety of dental impressions, they examined more than 1,000 human dentitions and studied hundreds of bite marks in cadaver skin. With the help of computer analysis and applied statistics, the team then worked to match its database of bite marks to the correct dental impressions.

“When the dental alignments were similar, it was difficult to distinguish exactly which set of teeth made which bites,” Sheets says. “That tells us that a single bite mark is not distinct enough to be linked to a specific individual. It can actually point to many different individuals.” This means that a false identification is possible, which can lead a police investigation away from the real perpetrator and toward an innocent individual.

The Canisius-UB studies are among the largest conducted on bite-mark analysis and the first to use human-skin models (rather than animal models, wax or Styrofoam). More notable is that its findings call into question criminal convictions that rested entirely on bite-mark evidence.

Since 2000, at least 25 people convicted on bite-mark evidence have been exonerated due to advances in DNA testing, according to the Innocence Project. The national organization, which works to free wrongfully convicted individuals, is now using the Canisius-UB studies to help build a case for having bite-mark evidence cast out of criminal proceedings.

“This is an example of where science can help prevent future wrongful convictions and perhaps even provide some social justice to those already convicted,” Sheets concludes.

In addition to Sheets’ research on bite-mark analysis, he is a member of the Expert Working Group on Human Factors in Handwriting Analysis. Appointed by the National Institute of Standards and Technology (NIST) and the National Institute of Justice (NIJ), which provide oversight to the federal forensic community, the Expert Working Group on Handwriting Analysis is one of several discipline-specific groups charged with identifying the human factors that affect the outcomes of forensic analyses and developing best practices, based on scientific research, that will reduce the likelihood of errors in the future.

Canisius College, a Jesuit, Catholic university, offers outstanding undergraduate, graduate and professional programs distinguished by transformative learning experiences that engage students in the classroom and beyond. We foster in our students a commitment to excellence, service and leadership in a global society.

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Joseph Peterson, Ira Sommers, Deborah Baskin, and Donald Johnson wrote in The Role and Impact of Forensic Evidence in the Criminal Justice Process:

Conclusions & Discussion

In spite of the increased attention paid to forensic evidence over the past decade, there is little published empirical data identifying the types of evidence routinely collected, and the extent to which this evidence is submitted to and examined in forensic crime laboratories. There is even less research that describes the role and impact of such evidence on criminal justice outcomes. While the current study shows that

forensic evidence can affect case processing decisions, it is not uniform across all crimes and all evidence types; the effects of evidence vary depending upon criminal offense, variety of forensic evidence, the criminal decision level, and other characteristics of the case. The current study attempted to fill this gap in knowledge by examining the role and impact of forensic evidence on five felony crimes across five jurisdictions….

https://www.ncjrs.gov/pdffiles1/nij/grants/231977.pdf

The Canisius College study is important because it examines whether one type of forensic evidence has the validity to be used to support convictions in criminal cases.

Resources:

Bite-mark Analysis                                                                                                                   http://science.howstuffworks.com/forensic-dentistry3.htm

It literally started with a witch hunt: A history of bite mark evidence                                           https://www.washingtonpost.com/news/the-watch/wp/2015/02/17/it-literally-started-with-a-witch-hunt-a-history-of-bite-mark-evidence/

Cases Where DNA Revealed that Bite Mark Analysis Led to Wrongful Arrests and Convictions                                                                                                                                 http://www.innocenceproject.org/news-events-exonerations/cases-where-dna-revealed-that-bite-mark-analysis-led-to-wrongful-arrests-and-convictions

Where information leads to Hope. © Dr. Wilda.com

Dr. Wilda says this about that ©

Blogs by Dr. Wilda:

COMMENTS FROM AN OLD FART©
http://drwildaoldfart.wordpress.com/

Dr. Wilda Reviews ©
http://drwildareviews.wordpress.com/

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