Monthly Archives: August 2011

Free Online Forensic Training

If you are encountering an issue of forensic science for the first time or if you’re looking for an in-depth training on a specific topic, online forensic trainings are a great way to access the knowledge of national experts from the comfort of your home or office.

I’ve compiled over 100 of these free trainings and put them in the training section the IDS Forensics website. Topics include crime scene investigation, DNA evidence, child abuse, toxicology, working with experts, and many more.  Some of the training organizations require you to register before you take the training, but it just takes a few minutes to sign up.

These online trainings are sponsored by the National Institute of Justice, the National Clearinghouse for Science, Technology & the Law, the Women’s Information Network and local organizations – RTI International, and the UNC School of Government. Check them out!

Here’s the link: www.ncids.com/forensic/resources/training.asp

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Legislative Change Regarding Expert Testimony

By Alyson Grine, UNC School of Government Defender Educator

In S.L. 2011-283 (H 542), the General Assembly revised North Carolina Evidence Rule 702(a). Rule 702(a) guides the trial court in serving a gatekeeper function with regard to expert testimony; the trial court must make a preliminary determination as to whether a witness has the qualifications to testify as an expert, and if so, whether the expert’s testimony is admissible. S.L. 2011-283 was enacted as a part of new limits in civil tort actions; however, the amended rule applies to criminal cases as well as civil. Thus, criminal defenders are asking: to what extent has the framework for determining the admissibility of expert testimony changed?

The amendments to Chapter 8C, Rule 702(a) read:

(a) If scientific, technical or other specialized knowledge will assist the trier of fact to understand the evidence or to determine a fact in issue, a witness qualified as an expert by knowledge, skill, experience, training, or education, may testify thereto in the form of an opinion.opinion, or otherwise, if all of the following apply:

(1) The testimony is based upon sufficient facts or data.

(2) The testimony is the product of reliable principles and methods.

(3) The witness has applied the principles and methods reliably to the facts of the case.

The legislation does not alter the language pertaining to the qualifications of an expert. Instead, the legislation adds the above subparts to impose restrictions on the admissibility of expert testimony. The subparts are lifted verbatim from Federal Rule of Evidence 702 as amended in 2000, which was intended to codify the criteria for the admissibility of expert testimony established in Daubert v. Merrell Dow Pharmaceuticals, 509 U.S. 579 (1993). Daubert established the modern standard for admitting expert testimony in federal trials; the Court set out five factors for trial judges to use as a measure of reliability in making a preliminary determination about the admissibility of scientific evidence:

  1. Is the evidence based on a testable theory or technique;
  2. Has the theory or technique been subjected to peer review and publication;
  3. Does the technique have a known error rate;
  4. Are there standards controlling operation of the technique; and
  5. To what degree is the theory or technique generally accepted by the scientific community? Id. at 593-94.

In Howerton v. Arai Helmet, Ltc., 358 N.C. 440 (2004), the North Carolina Supreme Court rejected the federal standard for determining the admissibility of expert testimony. “North Carolina is not, nor has it ever been a Daubert jurisdiction.” Id. at 469. Instead, North Carolina has used the three-part inquiry set forth in Howerton: “(1) Is the expert’s proffered method of proof sufficiently reliable as an area for expert testimony? (2) Is the witness testifying at trial qualified as an expert in that area of testimony? (3) Is the expert’s testimony relevant?” Id. at 458, relying on State v. Goode, 341 N.C. 513, 527-29 (1995) (internal citations omitted). The first prong of the Howerton test includes a requirement that the expert’s method of proof be reliable, much like the second restriction in amended Rule 702(a). Unlike amended Rule 702(a), however, the Howerton test does not explicitly require that experts have sufficient facts and data for their opinions, or that they apply their methods reliably to the facts. Arguably, these were implicit requirements under Howerton as they are components of reliability. Some North Carolina decisions have recognized that experts should have sufficient facts and data for their opinions and should apply their methods reliably. See, e.g., State v. Grover, 142 N.C. App. 411, aff ’d per curiam, 354 N.C. 354 (2001). Amended Rule 702(a) makes it clear that trial judges must apply those requirements before allowing expert testimony before the jury.

The approach that North Carolina adopted in Howerton was “less mechanistic and rigorous than the exacting standards of reliability demanded by the federal approach.” Howerton, 358 N.C. at 464 (internal citations omitted); see also Robert P. Mosteller et al., North Carolina Evidentiary Foundations at pp. 10-15 to 10-17 (2d ed. 2006). Amended Rule 702(a) may or may not mandate the precise approach required by Daubert, but by adopting the language of Federal Rule 702, the General Assembly has raised the bar (or better stated, “the gate”), thereby requiring greater scrutiny of expert testimony than the former North Carolina rule and the cases interpreting it. Court actors should not presume that a method of proof that was deemed sufficiently reliable under the former North Carolina rule and Howerton will be admissible under the amended rule. The subparts added by S.L. 2011-283 are not a codification of Howerton, and it may no longer be good law. See Daubert, 509 U.S. at 586-87 (holding that the “general acceptance test” of Frye v. United States,54 App. D.C. 46 (1923) was superseded by the adoption of the Federal Rules of Evidence). In response to the legislative changes, defenders should be prepared to conduct more rigorous scrutiny of experts to determine admissibility, which will require probing discovery, motions, and voir dire practices to determine whether the expert’s testimony complies with the amended requirements.

As mentioned above, the amendments to Rule 702(a) are part of the “An Act to Provide Tort Reform for North Carolina Citizens and Businesses.” Possibly, the General Assembly did not have an eye to the impact the amendments would have on criminal practice in North Carolina. However, recent cases reveal growing concerns about unreliable expert testimony in criminal cases.  See State v. Ward, 364 N.C. 133 (2010) (expert’s testimony was not based on sufficiently reliable method of proof where expert identified substances based on a visual examination rather than a chemical analysis); State v. Davis, __ N.C. App. __, 702 S.E.2d 507 (2010) (expert’s testimony was not based on sufficiently reliable method of proof where expert relied on odor analysis to conduct retrograde extrapolation of defendant’s blood alcohol concentration at time of accident); State v. Meadows, __ N.C. App. __, 687 S.E.2d 305 (2010) (expert’s testimony was not based on sufficiently reliable methods of proof where expert relied on the results of the NarTest machine). Thus, amended Rule 702(a) may be viewed as a timely reform in the criminal context.

Note: A later bill (SL 2011-317) makes the revised rule applicable to actions arising on or after October 1, 2011. For criminal cases, the rule likely applies to cases in which the offense occurred on or after that date.

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Forensic Tests for Saliva: What you should know

By Maher Noureddine, Ph.D.

First in the series: Bodily Fluids and Forensics

You may encounter cases in which the prosecution claims that SBI tests establish the presence of human saliva on the victim as part of its proof that an assault occurred. This type of evidence is often seen in sexual assault cases.  In cases like this it is important to understand how the SBI or law enforcement tests for saliva and how the problem of false positives limits those tests.

The non-invasive nature of saliva sample collection has earned that bodily fluid significant medical attention. Saliva tests can reveal certain disease markers, viral infections, and the presence of therapeutic as well as illicit drugs in the body. Saliva is rich in the enzyme alpha-amylase (a.k.a. α-amylase, salivary amylase, or Ptyalin), an enzyme that breaks down complex carbohydrates into smaller sugar molecules. The biological function of this enzyme was first described by Erhard Friedrich Leuchs in 1831.

Almost 100 years later (1928), the German investigator B. Mueller conceived the use of alpha-amylase as a forensic target to validate the presence of saliva on a given surface. This idea gained popularity, and for the next 50 years several investigations endeavored to refine and enhance the methods to test for alpha-amylase. However, some important caveats continue to limit this test as a presumptive or screening test for human saliva, even to this day. Alpha-amylase is an enzyme that has changed very little throughout the process of evolution: alpha-amylases from bacteria, fungi, or chimps are very similar in structure and function to that of the human alpha-amylase. In humans, there are at least four variants (or versions) of alpha-amylase, two of which are found in saliva, and the other two are secreted in the pancreas. Those variants are almost indistinguishable at the enzymatic activity level. Because the presumptive test for saliva detects the enzymatic activity of alpha-amylase, and not alpha-amylase molecule itself, that test will yield a positive result if any alpha-amylase enzyme is present, regardless of the organism it came from.

Crime labs, including the SBI lab (See p. 13 of their protocol here) use a reagent (chemical) called Phadebas to conduct this presumptive test for alpha-amylase. This test is relatively cheap, quick, and highly sensitive to any alpha-amylase enzymatic activity. Myers, J. and Adkins W., Comparison of modern techniques for saliva screening, 53 J Forensic Sci 4 (2008).  However, it is important to keep in mind that this test alone cannot confirm the presence of human saliva because this presumptive test will give a positive result if the alpha-amylase enzyme from any organism is present.

Laboratory tests for saliva remained presumptive until the late 1980s, when a group of researchers in Japan succeeded in developing a monoclonal antibody that is specific for the alpha-amylase variant that is present in human saliva in particular. Ito, K. et al., Preparation of human salivary alpha-amaylase specific monoclonal antibody, 97 J Biochem 5 (1985). Therefore, instead of testing for enzymatic activity, now we can detect the alpha-amylase molecule itself, and specifically, the alpha-amylase from human saliva. This ushered the development of test kits that are now being used in forensic laboratories around the world to screen for human saliva (known to many as Lateral Flow Immunochromatographic Strip Test or Rapid Stain Identification (RSID) Saliva kits).  The SBI lab used a combination of the presumptive Phadebas test and the RSID test to “confirm” the presence of human saliva (See p. 14 of their old protocol here).  The SBI lab protocols have been updated recently and reflect important changes in interpretation language.  Under current protocols (see p. 2, available here), the SBI lab acknowledges that the RSID test for saliva is a presumptive test.

The RSID-Saliva kits have been tested on samples from various types of surfaces such as paper, cigarette butts, plastic and glass bottles, and metal cans. The specificity of RSID-Saliva kits has been scrutinized by researchers. Although RSID-Saliva kits were found to be sensitive and specific to human saliva, positive reactions were also noted in samples containing alpha-amylases from  mammals such as  gorillas and rats. Positive reactions were also noted in other bodily fluids such as semen, blood, vaginal discharge and sweat. See Old J. et al., Developmental Validation Studies of RSID-Saliva Lateral Flow Immunochromatographic Strip test for the forensic detection of Saliva, Independent Forensics (2010); Pang, B. et al., Applicability of Two Commercially Available Kits for Forensic Identification of Saliva Stains, 53 J Forensic Sci 5 (2008). The RSID-Saliva test gives positive results from breast milk, likely because the presence of alpha-amylase aids the nursing infant in food digestion. High reactivity of this test is also observed in samples containing human feces. Not surprisingly, humans swallow copious amounts of saliva, which travels through the entire digestive system and, as a result, alpha-amylase from saliva (as well as alpha-amylase from the pancreas) is thought to reach the colon where it can mix with fecal material. You will note that the SBI lab’s procedure is to not use this test on rectal samples. Reactivity was also noticed in urine samples, a result that remains inconsistent between studies. Butterworth, P. et al., Human α-amylase and starch digestion: An interesting marriage, Starch 63 (2011). These limitations clearly demonstrate why the RSID-Saliva test is presumptive in nature.

It is important to consider these limitations when examining or reviewing tests for the presence of the assailant’s saliva based on swabs from sexual assault kits. Improper swabbing and other factors relating to personal hygiene, personal behavior, and indirect saliva transfer from mouth to surface can result in “false” positives. Since saliva can harbor mucosal cells from the perpetrator, the validation of the saliva sample can be coupled with forensic DNA analysis (STR/Y-STR) to rule in or rule out the connection between an individual and the forensic evidence. If DNA analysis not completed, it is worth questioning whether the positive test for saliva could be caused by personal hygiene practices or another innocent explanation for the presence of the salivary amylase.

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Bodily Fluids and Forensics: Introduction to the Series

By Maher Noureddine, Ph.D. and Sarah Rackley

The field of forensic investigation continues to reap tremendous benefits from advancements made in various scientific disciplines including physics, chemistry, biology and others. The detection and analysis of biological molecules have been at the forefront of this advancement, even to the level of revolutionizing forensics as we know it. Arguably, DNA takes center stage as the molecule with the most impact. There are, however, other biological molecules that have played a significant role in forensics for many decades, and will continue to do so for years to come.

In this blog series, we will highlight such molecules, the bodily fluids they lurk in, the important issues relating to their detection and analysis in forensics, and what you might want to know when confronting this type of evidence. The bodily fluids we will examine include: saliva, blood, and semen.

We will start this series on Monday by tackling salivary amylase, the biological molecule that is found in saliva and the main target for analysis when examining saliva as a forensic sample in cases such as murder, kidnapping, sexual assault, and others. Stay tuned for Dr. Noureddine’s first post in this scientific series.

Dr. Noureddine is a doctor in molecular genetics with extensive background and experience in scientific research and training in human genetics. He has a B.S. in Biology from Radford University in Virginia, an M.S. in Molecular Biology from the University of North Carolina at Greensboro, and a Ph.D. in Molecular Genetics from the University of North Carolina at Chapel Hill. He completed a postdoctoral fellowship at Duke University Medical Center (The Center for Human Genetics), where he published many articles on the genetics of Parkinson Disease and other human genetic disorders. He was also a Senior Fellow at the National Institute for Environmental Health Sciences/National Institute of Health, where he conducted research in cancer using advanced methodologies in genomics. His expertise include specialized training in complex genomics, DNA fingerprinting, SNP analysis, mitochondrial genetics, and state of the art methodologies in genetic variations in the population. He owns and operates ForensiGen, LLC, a consulting company that specializes in DNA forensics, biological evidence, and disease genetics. His profile can be found here. His email address is mnoureddine@theiacd.com.

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COA addresses bad lab reports in Duke Lacrosse case

By Daniel Shatz, Assistant Appellate Defender

For those of you who just cannot get enough Duke Lacrosse news, the Court of Appeals issued an opinion on August 2, 2011 in a civil case involving a lawsuit filed by the DNA tester, Brian Meehan, against his former company, which had fired him “for cause.” Not surprisingly, the Court held that submitting an incomplete lab report that obscured the test results constituted just cause to fire Meehan both under the express terms of his employment contract and as a matter of public policy.

Although it is a civil case about employment rights, the Court’s language regarding public policy and incomplete, obscuring lab reports should be helpful for anyone working on a case involving bad SBI lab reports. The case is Meehan, v. American Media Int’l. The most helpful language is at p. 26-27 of the slip opinion:

In the present case, Plaintiff’s misconduct involves intentionally obscuring evidence and submitting an incomplete report in a court of law when clear explanation of the test results would have exculpated individuals wrongly charged. We believe public policy supports the conclusion that such misconduct is grounds for just cause termination of employment.

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Recommendations of the Ombudsman to the SBI

The NC Attorney General’s Office has released the Report of the Ombudsman, completed by Judge Vince Rozier, Jr. prior to leaving that position. The Ombudsman’s report is preceded by a memo from the Acting North Carolina State Crime Lab Director Joseph R. John, Sr. responding to the report’s recommendations.

A few of the recommendations that stood out include the following:

  1. Publish past protocols and procedures of the SBI lab, in addition to the current procedures (see p. 13). While the current procedures for most sections of the lab have been posted on the NCDOJ’s website, historical procedures have not been posted, despite the recommendations of the Swecker Report from August 2010.
  2. Make clear where standards have been modified and include former and current status of the standard (see p. 13-14). To demonstrate the importance of denoting changes, Rozier points to a 2008 Administrative Order that changed the standard for what conclusions can be drawn regarding minor profiles in DNA mixtures. (Prior to the 2008 order, if a DNA sample contained more than one person’s profile, analysts could report that the defendant “cannot be excluded as the contributor to the minor allele” if the defendant’s DNA was observed as a minor profile at a minimum number of locations. The new standard requires analysts to state “no conclusion can be rendered as to the donor of the minor profile” if the same results are observed.) Attorneys should be made aware of changes to procedures regarding interpretation of results and acceptable conclusions and should be aware of which standard is being used in their case.
  3. Along this line, Rozier recommends that prior to court, analysts review any difference in the reporting language used at the time the test was performed and the current standard (see p. 24-25). Further, he recommends that where reporting language has been modified, analysts provide the most current reporting standard during their testimony in court (however, the lab’s current practice is for analysts to testify according to the reporting language in place at the time the test was performed) (see p. 25). An attorney who is aware of a change in reporting standard may be able to question the basis for an analyst’s conclusion that is based on an outdated reporting standard. (For example, consider how the lab’s standard for reporting (or not reporting) the results of negative confirmatory tests for blood has changed and the importance of understanding which standard is being used.)
  4. Rozier also recommended that a group of criminal justice stakeholders be formed to review the Evidence Submission Form (SBI-5) to ensure the form promotes neutrality (see p. 19-20).

This is just a handful of the recommendations that I found to be significant. I welcome posts in the comments section about these or other recommendations.

Yesterday, the News and Observer article Long delays in SBI reforms stirs critics covered this report and responses to recent announcements by the Attorney General regarding the Crime Lab.

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Texas court upholds exclusion of unreliable scent-lineup evidence

A Texas appeals court affirmed the exclusion of evidence that a dog identified a defendant’s scent in a “scent-lineup” in State v. Dominguez. The trial court found that human scent identification by a canine is not sufficiently reliable to be admitted in evidence in a criminal trial, based on the defendant’s motion to suppress and the testimony of a state and a defense expert. The appeals court affirmed that finding.

It may be worthwhile to take a look at the defendant’s arguments regarding reliability, especially in light the recent North Carolina legislation. Session Law 2011-283 makes several changes to the Rules of Evidence, including new tort limits, but the changes to G.S. 8C-702(a) apply to expert testimony in criminal cases as well. The rule requires for expert testimony, as a condition of admissibility:

(1) The testimony is based upon sufficient facts or data.
(2) The testimony is the product of reliable principles and methods.
(3) The witness has applied the principles and methods reliably to the facts of the case.

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