Thursday, August 29, 2013

Forensic Expert Testification in a Case

Forensic Expert Testification in a Case

The fatal shooting of Trayvon Martin by George Zimmerman took place on the night of February 26, 2012, in Sanford, Florida, United States. Martin was a 17-year-old African American high school student. George Zimmerman, a 28-year-old. Following an earlier call from Zimmerman, police arrived within two minutes of a gunshot during an altercation in which Zimmerman fatally shot Martin, who did not have any weapons. Zimmerman was taken into custody, treated for head injuries, then questioned for five hours. The police chief said that Zimmerman was released because there was no evidence to refute Zimmerman's claim of having acted in self-defense, the police were prohibited by law from making an arrest. The police chief also said that Zimmerman had had a right to defend himself with lethal force. As news of the case spread, thousands of protestors across the country called for Zimmerman's arrest and a full investigation. 

Tuesday, August 27, 2013

'Medical tests should be more sensitive to rape victims'

    MUMBAI: Going strictly by textbooks on forensic medicine, doctors should be suspicious of any well-built woman who claims to have been raped. According to the textbooks, "a well-built woman cannot be raped", "most cases are false", and "a working class woman cannot be raped as she can offer resistance".

    Experts say the existing protocols of medical examination of a sexual assault victim place undue emphasis on injury documentation that looks for signs of resistance on the victim's body, examination of hymen, assessment of virginity and two-finger test to determine the size and laxity of vaginal opening, rather than the health problems the victim may suffer from.

    Padma Deosthali, coordinator of the Centre for Enquiry into Health & Allied Themes (CEHAT), an organization which has been working with sexual assault victims, said the medical examinations are part of the whole process which have to be carried out to prove whether the crime was committed. However, many parts of this exercise are not in touch with the reality and circumstances of the victim.

    "The body swabs, for instance, would test positive only if there has been forced peno-vaginal intercourse with ejaculation.

    DNA tests cannot distinguish identical twins on rape charge

    The  brothers were arrested after DNA evidence taken from the scene linked the alleged crime with one or both of them.
Picture shows Aftab Asghar (left) and Mohammed Asghar (right).
    Aftab Asghar (left) and Mohammed Asghar (right) were arrested after DNA evidence taken from the scene linked the alleged crime with one or both of them. Photo: INS NEWS AGENCY
    Prosecutors charged both Mohammed and Aftab Asghar but said it may be "that only one of the defendants faces trial."
    The pair, aged 22, were expected to enter pleas when they appeared alongside each other in the dock at Reading Crown Court, Berks.
    But police and the Crown Prosecution Service are still trying to determine whether they should continue to pursue the case against both men, and prosecutor Sandra Beck requested more time for the Crown to pursue particular lines of inquiry.

    Monday, August 26, 2013

    Body of evidence: A radical approach to forensic pathology (Virtopsy)

    Virtual cadavers, needle-wielding robots – and not a scalpel in sight. Laura Spinney meets the research team behind the 'virtopsy', a radical approach to forensic pathology

    Backing his four-by-four into his garage one night in 2006, after returning from a drunken party in the Swiss canton of Bern, a man crushed his wife against the garage's rear wall.

    He called an ambulance, but she died before it reached the hospital. The man claimed it was a tragic accident – he had reversed once and hadn't seen what he was doing – and to the police it looked like a case of involuntary manslaughter. But just to be sure, they asked Michael Thali, director of the University of Bern's Institute of Forensic Medicine, for a second opinion.
    Prof Thali and his team carried out an autopsy on the woman, but not the kind we're used to seeing in television shows such as CSI and countless police dramas. This was a scalpel-free, virtual autopsy, or "virtopsy" – a radical new approach to forensic investigation, in which Professor Thali is one of the pioneers.

    What forensics can say about Syria chemical attack

    The calls are getting louder. Even Russia, Syria's main ally, is now urging the Syrian government to allow weapons inspectors to investigate the site of Wednesday's alleged chemical attack on the suburbs of Damascus, held by rebels opposing President Bashar al-Assad's regime. This brings Russia in line with the US and the 36 other countries that yesterday called for a swift investigation into the apparent deaths of over 1000 men, women and children.

    Fingerprint Brushes Can Contaminate DNA Evidence

    Fingerprint brushes can become easily contaminated. Brushes can retain the DNA picked up. To make sure you don’t transfer DNA from a brush used at one scene to the next, use a new one at each scene. The brush used in a homicide case should become part of the evidence.An investigator can do simple things to ensure the integrity of DNA evidence. DNA can be transferred from one crime scene to another through tools. For example, fingerprint brushes can become easily contaminated. Brushes can retain the DNA picked up. To make sure you don’t transfer DNA from a brush used at one scene to the next, use a new one at each scene. This is most important on homicide cases where the DNA may be the determining factor. In fact, on homicides, the brush used should become part of your overall evidence. Remember that not only the brush used, but the powder itself can become contaminated.

    India’s Doubting Fathers and Sons Embrace DNA Paternity Tests

    Senior Congress leader N.D. Tiwari, wearing a white cap, with his biological son Rohit Shekhar, fourth from right, on the former's birthday. 
    Courtesy of Rohit Shekhar and Senior Congress leader N.D. Tiwari, wearing a white cap, with his biological son Rohit Shekhar, fourth from right, on the former’s birthday.
    In 2007, a 28-year-old man was propelled from obscurity to prominence when he turned to the Delhi High Court to seek a public acknowledgement of paternity from a senior Congress Party leader, N.D. Tiwari. Rohit Shekhar, who said that he was the result of an affair between his mother and Mr. Tiwari, spent five years trying to force the politician to take a DNA test, taking his case all the way to the Supreme Court, which ruled in Mr. Shekhar’s favor last year.
    The high-profile nature of the case contributed to the public’s growing awareness of the role of DNA in establishing biological ties, and these days, paternity tests are much more commonplace, with private labs offering home testing kits for 10,000 rupees ($160) or less, with no need for a judge’s permission. A person can swab the inside of a child’s mouth at home, send the samples from the adult and child back to the lab and receive the results within two weeks.

    Ritu, the director of DNA Center India in Hyderabad, said her company has seen a clear increase in interest in its DNA paternity tests in recent years. “Initially, we could get around 10 calls a month, but over the last two years or so this has increased to around 40,” said the director, who goes by one name. Not every call leads to an order, she said, but “those who do avail of our services tend to opt for the ‘peace of mind’ home testing kit.”
    People have a variety of reasons for ordering paternity tests, but some DNA testing centers say that many clients are doubting fathers or men who are seeking to end a marriage, and it’s this group that worries some advocates of women’s rights. Veena Gowda, a lawyer in Mumbai who has been practicing for over 15 years, contends that these men are using the tests to deprive women of their right to alimony or child support by accusing the women of adultery, which is illegal in India.
    “It’s almost as if science is always twisted to suit patriarchal norms,” Ms. Gowda said. “Putting a child through paternity tests without court orders only reinforces the thought that marriage is nothing more than controlling a woman and her womb.”
    In the United States, the demand for paternity tests is fueled in part by the Personal Responsibility and Work Opportunity Act of 1996, which gave child-support agencies the authority to order DNA tests without prior judicial consent. State-based child support enforcement agencies remain some of the biggest clients for DNA paternity tests. However, the technology revealed its double edge when men began using it not just to establish paternity but to distance themselves from the burden of child support once they could prove the absence of biological ties.
    Indian courts have been circumspect in ordering paternity tests, especially in the death throes of a marriage. Currently, the law places less weight on DNA ties and instead establishes the marital presumption of paternity, which sees the husband as the father of any children conceived during the marriage. Children born during a legal union or within 280 days after a marriage has dissolved are considered the legitimate offspring of the husband, unless the husband can prove that he had no access to his wife during the time the child would have been conceived.
    Even when DNA evidence proves a biological tie between a father and child, the courts will still continue to favor longstanding familial relationships over genetics. In the Tiwari case, for example, the DNA test showed that the Congress leader was indeed Mr. Shekhar’s biological father, but the law still considers B.P. Sharma, who was married to Mr. Shektar’s mother when Mr. Shektar was born, as the legitimate father. (Mr. Shektar’s legal battle continues as Mr. Tiwari has refused to accept the results of the DNA test and declined to participate in the court mediation process.)
     Women are generally entitled to spousal support after a divorce, but a paternity test that shows no biological connection to a child can be used by a man to get an exemption from paying alimony and child support. However, lawyers say that courts have on occasion ordered a nonbiological father to offer some financial support to prevent the child from living in poverty and to minimize psychological damage.
    The courts have been reluctant to order paternity tests even when the petitioner is the mother. A few years ago, a woman from Orissa approached the Orissa State Women’s Commission asking that a paternity test be conducted after her estranged husband claimed he was not the father of her child. The commission granted permission, and the decision was upheld by the Orissa High Court. The husband challenged the decision in the Supreme Court, arguing that the test was an invasion of his privacy and that the divorce had not been finalized.
    In 2010, the Supreme Court ruled that a paternity test to determine the identity of a child especially during matrimonial disputes should not be done in a routine manner because it infringes on the right to privacy and may have a devastating effect on the child. “Sometimes the result of such scientific test may bastardize an innocent child even though his mother and her spouse were living together during the time of conception,” the judges said in their ruling.
    Currently, DNA home testing kits are not considered admissible in court because there is no verifiable chain of custody. A court-ordered paternity test has to be conducted in a government-certified forensic center with a chain of custody to ensure that the evidence has not been tampered with.
    Private labs do offer more expensive DNA tests that follow a documented chain of custody, which can be presented as evidence in court. Ms. Gouda, who has challenged the legality of such tests in court cases, finds them unethical.
    “The authority is with the courts to determine whether a paternity test should be ordered. The principal of the law is to protect the child,” she said.
    Women’s rights activists are concerned that as cohabitation without marriage and divorce become more common as Indian society changes, the demand for paternity testing will rise, which they say would ultimately harm the children involved if the courts indiscriminately order DNA tests.
    Kanti Sathe, who has been practicing family law in Mumbai for 25 years, predicted that this decade will see more people seeking paternity tests. She said she doesn’t oppose paternity testing in all cases – in fact, such tests could help a child with unmarried parents receive financial support from the father. “Children are entitled to financial support and inheritance from their biological father. What we can count on, and what is always required is judicial discretion.
    “What’s being played out in courts is the conflict between encroaching on an individual’s right to privacy and the rights of a child,” said Ms. Sathe.
    She recalled one of her recent cases, in which the couple was seeking a divorce, and the husband, unwilling to pay child support, claimed that he was not the father of their child. The matter was resolved outside the court when he backtracked from taking a paternity test. “He accepted that the child was his, and a settlement was reached. Imagine the damage it would have inflicted on the child if our courts insisted on paternity tests for every case,” said Ms. Sathe.
    DNA home tests also come with legal pitfalls for the labs themselves. Ravi Kiran Reddy, director of DNA Labs India in Hyderabad, is being sued by the wife of a client who had recently approached the lab for a home paternity test. The test found that there was a 99.9 percent chance that the client was not the father of the child, as he was led to believe. However, the mother is now challenging the result in court and blaming the biotechnology company for tarnishing her reputation, said Mr. Reddy.
    “It’s not worth the trouble, really,” he said. “The DNA sequencing machines we use cost crores [tens of millions] of rupees, and genetically testing for parenthood does not even cover the cost of running the laboratory or maintaining the equipment.” The bulk of the forensic center’s work comes from clients asking for their DNA to be sequenced for health reasons and those who need to establish familial ties either for immigration or for an infant born via a gestational surrogate.
    This is the sort of legal complication that will occur repeatedly if men are allowed to use these tests to accuse their wives of infidelity, women’s rights advocates say.
    “If home testing kits were legally admissible, every person would be under the scanner, every woman be suspect of cheating, and every child’s paternity questioned,” said Ms. Sathe.

    Anjali Thomas is a recent graduate of the Columbia University Graduate School of Journalism. Ms. Thomas has worked with the Times of India and Daily News and Analysis in Mumbai.

    Software That Exposes Faked Photos

    Chris Gash
    Using algorithms designed to sniff out suspicious shadows, computer scientists from Dartmouth and the University of California, Berkeley, say they have developed software that can reliably detect fake or altered photos.

    The technique could be useful in the emerging field of photo forensics, said Hany Farid, a Dartmouth computer science professor and developer of the software. In the age of Photoshop, detecting manipulated photos is a growing priority for lawyers, journalists and people involved in law enforcement and national security.
    To determine an image’s authenticity, the software uses geometric formulas to analyze shadows to determine if they are all physically consistent with a light source. Inconsistencies with the light or within the shadows themselves — some of which may be invisible to the naked eye — indicate the photo is doctored.
    Analyzing shadows is a common technique in photo forensics, said the study, being published in the September issue of ACM Transactions on Graphics. But the eye simply cannot compete with the sophistication of today’s image-manipulation software.
    “Perceptual studies show that the brain is largely insensitive to gross inconsistencies in shadows,” Dr. Farid said. “That means that an analyst may not be very good at determining whether shadows are real or not. But more importantly, it means a forger may not notice when he or she places an incorrect shadow on an image.”
    To demonstrate the software, the researchers ran an analysis of a picture of the 1969 moon landing. They determined that the image was not a fake. 

    Familiar DNA Leads to Arrest in Virginia

    A familial DNA search has helped authorities in Virginia to find and arrest a suspect. Virginia is one of only a handful states that use the genetic material from relatives to track suspects in violent crimes who have left DNA at a crime scene but whose genetic fingerprint is not contained in any database.A familial DNA search has helped authorities in Virginia to find and arrest a suspect.
    The Virginia Department of Forensic Science confirmed the arrest. But officials would not provide details at the request of a local prosecutor and the law enforcement agency that requested the search, the Richmond Times-Dispatch ( reported.
    Several cases linked by DNA appeared to have been the work of the same person, said Brad Jenkins, program manager for the department’s forensic biology section. He did not specify the type of crime or crimes.
    “We conducted a familial search and came up with a possible relative of the perpetrator. Police did their investigation and we did additional DNA (testing) and a person was arrested,” Jenkins told the newspaper.
    Virginia is one of only a handful states that use the genetic material from relatives to track suspects in violent crimes who have left DNA at a crime scene but whose genetic fingerprint is not contained in any database.
    Some states have shunned the controversial approach to track violent offenders because of privacy or fairness concerns. It was approved for use in Virginia in 2011.
    Virginia, a national leader in DNA testing, requires that persons convicted of certain crimes provide a sample of their DNA for inclusion in a state databank. When DNA found at a crime scene does not match any genetic fingerprint in state or national databases, investigators often run into a dead end in important cases that have gone cold.
    Under the familial DNA program, genetic profiles left at crime scenes can be used to find near-matches in databases that could be a suspect’s close relative. Then investigators hunt down the suspect to get his or her DNA sample for a traditional DNA test.
    In California, a familial DNA search led to the arrest in 2010 of a suspect in the “Grim Sleeper” slayings in the Los Angeles area. Investigators were led to Lonnie Franklin Jr. after his son was arrested on an unrelated matter and swabbed for DNA. The sample came back as similar to evidence in the serial killings. Franklin has pleaded not guilty to 10 counts of murder and one attempted murder charge.
    Source: Associated Press

    Saturday, August 24, 2013

    Traditional Medicines Found To Contain Toxins And Illegal Ingredients

    Traditional Medicines Found To Contain Toxins, Allergens, And Illegal Ingredients

    Health & Medicine
    Researchers have discovered that some traditional Chinese medicines contain potentially toxic plant ingredients, allergens, and even traces of endangered animals.
     Researchers at Murdoch University have used new DNA sequencing technology to study the animal and plant composition of traditional Chinese medicines (TCM) – with worrying results.
    The results, published in the journal PLoS Genetics, revealed that some TCMs contained potentially toxic plant ingredients, allergens and even traces of endangered animals.
    “TCMs have a long cultural history but today, consumers need to be aware of the legal and health safety issues before adopting them as a treatment option,” said research leader and Murdoch University Australian Research Council Future Fellow, Dr. Mike Bunce.
    Fifteen TCM samples, seized by border officials, in the form of powders, tablets, capsules, flakes and herbal teas were audited using the DNA preserved in the samples. In total, the researchers found 68 different plant families in the medicines, representing complex mixtures of species.
    “Some of the TCMs contained plants of the genus Ephedra and Asarum. These plants contain chemicals which can be toxic if the wrong dosage is taken, but none of them actually listed concentrations on the packaging,” said Bunce.
    “We also found traces from trade restricted animals that are classified as vulnerable, endangered, or critically endangered, including the Asiatic black bear and Saiga antelope.”
    Until now it has been difficult to determine the biological origins of ingredients contained within TCMs because processing into pills and powders makes identification difficult. Using second-generation, high throughput sequencing, the team was able to apply DNA techniques to audit the species composition.
    Another worrying concern is the mislabeling of TCMs meaning consumers are unaware of the presence of some ingredients including animal DNA and potentially allergens such as soy or nuts.
    “A product labeled as 100 percent Saiga antelope contained considerable quantities of goat and sheep DNA,” Bunce said. “Another product, Mongnan Tianbao pills, contained deer and cow DNA, the latter of which may violate religious or cultural strictures.”
    Incorrect labeling makes it difficult to enforce legislation and to prosecute cases of illegal trade.
    “It is hoped that this new approach to genetically audit medicinal products will bring about a new level of regulation to the area of complementary and alternative medicine,” Bunce said.
    Bunce and his team have applied for funding from the Australian National Health and Medical Research Council (NHMRC) to expand the use of these new DNA tests in other wildlife forensic applications, such as to evaluate other herbal medicines.
    The article can be found at: Coghlan ML et al. (2012) Deep Sequencing of Plant and Animal DNA Contained within Traditional Chinese Medicines Reveals Legality Issues and Health Safety Concerns.
    Source: Murdoch University.

    New Forensic Technique for Analyzing Lipstick Traces

    New Forensic Technique for Analyzing Lipstick Traces
    Univ. of Kent

    A study by forensic scientists at the Univ. of Kent has established a new way of identifying which brand of lipstick someone was wearing at a crime scene without removing the evidence from its bag, thereby avoiding possible contamination.
    Using a technique called Raman spectroscopy, which detects laser light, forensic investigators will be able to analyse lipstick marks left at a crime scene, such as on glasses, a tissue, or cigarette butts, without compromising the continuity of evidence as the sample will remain isolated.
    Analysis of lipstick traces from crime scenes can be used to establish physical contact between two individuals, such as a victim and a suspect, or to place an individual at a crime scene.
    The new technique is particularly significant for forensic science as current analysis of lipstick traces relies on destructive forensic techniques or human opinion.
    "Continuity of evidence is of paramount importance in forensic science and can be maintained if there is no need to remove it from the bag. Raman spectroscopy is ideal as it can be performed through transparent layers, such as evidence bags. For forensic purposes Raman spectroscopy also has the advantages that microscopic samples can be analyzed quickly and non-destructively," says Prof. Michael Went of the University’s School of Physical Sciences.
    Raman spectroscopy is a process involving light and vibrational energy of chemical bonds. When a material — in this case lipstick — scatters light, most of the light is scattered at its original wavelength but a very small proportion is scattered at altered wavelengths due to changes in vibrational energy of the material’s molecules. This light is collected using a microscope to give a Raman spectrum which gives a characteristic vibrational fingerprint which can be compared to spectra of lipsticks of various types and brands. Hence it is possible to determine identity of the lipstick involved.
    Research into applying the same method on other types of cosmetic evidence, such as foundation powders, eye-liners and skin creams is also underway.
    Source: Univ. of Kent