Category Archives: Uncategorized

NIST urges caution in use of likelihood ratio

The National Institute of Standards and Technology (NIST) released an article last week calling into question the use of the likelihood ratio to present evidence in court. NIST states that there is uncertainty about the appropriate use of the likelihood ratio. An expert’s subjective opinion may affect the calculation of the likelihood ratio, potentially distorting the evidence. More information is available here.

Attorneys who see a likelihood ratio in a lab report should consider the NIST report and  investigate further prior to trial. Many labs are moving toward implementation of the likelihood ratio for interpretation of DNA analysis. To my knowledge, the NC State Crime Laboratory and the Charlotte-Mecklenburg Police Department do not employ the likelihood ratio in their interpretations of DNA evidence, though it could be adopted at some point in the future. The likelihood ratio is used by some private laboratories, such as NMS Laboratories.

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AAAS Report on Fire Investigation

Attorneys who are handling cases involving arson allegations should be aware of the Forensic Science Assessments: A Quality and Gap Analysis – Fire Investigation publication that was released this month (July 2017). The report was produced by the American Association for the Advancement of Science (AAAS).

The report looks at the discipline of fire investigations and identifies which parts are well founded in science and where gaps in knowledge exist. The report identifies 25 areas in need of additional research. The report is divided into the topics of fire scene investigation and fire debris analysis. The report concludes that canine alerts should not be relied upon unless confirmed by laboratory analysis (pp. 7, 18, 30). The report notes that some research has found erroneous conclusions about point of origin in excess of 75% (p. 5 of plain language version). Additional research regarding error rates is needed. (pp. 7-8). The report also contains an in-depth discussion of cognitive bias, the role it plays in fire investigation, and recommendations for minimizing bias in fire scene investigation (p. 8, 13, 26).

The full report is available for free download. A “plain language” summary version is also available.

The report is the result of a Working Group consisting of an academic fire engineer, an analytical chemist, a cognitive psychologist, and a forensic practitioner. The work was guided by an Advisory Committee which included a law enforcement official, a social scientist, a cognitive psychologist, a law professor, a judge, a biomedical researcher, a forensic scientist, and a statistician.

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SWGFAST Sufficiency Graph

The Scientific Working Group on Friction Ridge Analysis, Study and Technology (SWGFAST) has a sufficiency graph for fingerprint comparison that may be useful for attorneys to use when discussing fingerprint comparisons with experts.sufficiency-graph

The sufficiency graph reflects the interplay between quality and quantity of minutiae. Minutiae are small details that are used in comparing one print to another, such as ridge endings, bifurcations, and dots. These may also be called points of comparison or features of a print. This interplay between quality and quantity determines the level of complexity of a latent fingerprint. By using this graph, a fingerprint examiner should be able to explain her determination of whether a latent print could be individualized to a source.

In the graph above, the solid curve in the graph defines the lower limit of the sufficiency of friction ridge details below which, in area marked A, an individualization decision is not warranted. The dotted curve indicates the boundary between complex and non-complex prints. In area marked B in the graph, the examination is considered as complex and an individualization may be warranted. In area marked C, the examination is considered as non-complex and an individualization is warranted. See SWGFAST, Document #10, Standards for Examining Friction Ridge Impressions and Resulting Conclusions § 6.4.1.1 and § 6.4.1.5 (quotations omitted). Available here.

Additionally, the rarity of the features is factored into the examiner’s analysis and may adjust the position on the graph upward or downward on the graph between the zones.

An attorney could use this graph to discuss a comparison with a fingerprint examiner and arrive at a more concrete understanding of the level of complexity of the comparison. This graph was generated based on the collective experience of members of SWGFAST, not based on any scientific study. So, the curve is not intended to set a fixed requirement about number of points/minutiae, but it might be a starting point for a conversation. For example, if the print has 2 minutiae and low quality, the examiner would have some explaining to do about any individualization made to the source of the print. But, if the print is in a border area, then the examiner and the attorney could discuss why the examiner reached a certain conclusion or not.

Attorneys should read the entire SWGFAST Standards document for a better understanding of how examiners compare latent prints and make decisions about individualization. An understanding of the SWGFAST procedures and the procedures of the examiner’s own lab will improve communication between an attorney and an examiner and will help an attorney evaluate the forensic evidence in the case.

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NACDL Releases Primers on Surveillance

With a focus on Fourth Amendment concerns, the National Association of Criminal Defense Lawyers (NACDL) recently began a series of surveillance primers. The first primers in the series provide information on Automated License Plate Readers, Cell Phone Location Tracking, and Cell Site Simulators. NACDL will periodically release more primers on surveillance technologies. These documents are available to members and non-members here.

Each primer describes what the technology is designed to do, how it is used, and suggested defense strategies to identify and challenge the use of these technologies. The primers discuss law enforcement justifications for their use and provide lists of resources to aid in further research. These are a great starting point to further one’s understanding of these technologies, including determining if they were used in a case.

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Center for Nursing Excellence International Releases Multidisciplinary Sexual Assault Glossary

It can be frustrating when a term means something to one discipline yet has a different definition when used in another discipline. Thus, together with the Forensic Technology Center of Excellence (FTCoE), the Center for Nursing Excellence International (CFNEI) has released a glossary of terms used in sexual assault cases.  The Multidiscipline Sexual Assault Glossary is a continuously updated searchable database compiled with the input of experts in several fields.

With this glossary, attorneys can ensure clear communication with jurors as well as experts consulted in the course of sexual assault cases.  As the definitions are FBI-compliant, one can be confident in their veracity and clarity.  The glossary will be available as a smartphone app in the future.

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Toxicology Testing by NMS Labs – FAQ

Many attorneys have asked us about blood-drug (and some blood-drug and alcohol) testing performed by NMS Labs. We have compiled the questions and our answers here. If you have additional questions, please post them in the comments and we will try to answer them as well. Let’s make this a living document!

The toxicology evidence in my case was analyzed by NMS Labs in PA. Why was it sent there?

The NC State Crime Laboratory currently is outsourcing blood-drug and blood-alcohol and drug cases in an effort to address their backlog. 43 counties are currently participating in the outsourcing program: Alexander, Beaufort, Bladen, Brunswick, Buncombe, Burke, Cabarrus, Caldwell, Catawba, Cleveland, Columbus, Duplin, Durham, Edgecombe, Franklin, Gaston, Greene, Guilford, Harnett, Hoke, Iredell, Lenoir, Lincoln, Johnston, Jones, Lee, McDowell, Mecklenburg, Moore, Nash, New Hanover, Onslow, Rockingham, Rowan, Rutherford, Sampson, Scotland, Stokes, Surry, Union, Vance, Warren, Wayne, and Wilson.

Who is the “Certifying Scientist” who signs the lab report and are there any potential problems with this?

NMS lab reports are not signed by the analyst who performed the tests, rather by a “Certifying Scientist,” who does not seem to have any interaction with the evidence itself, and possibly not even the data. Melendez-Diaz established an inescapably clear requirement that those people testifying as experts, must have formed their own opinion on the data that was generated from the testing. If the Certifying Scientist does not have an opinion, or lacks the qualifications to support those opinions, that person should not be testifying as an expert about the data in that lab packet. Additionally, NMS runs their analyses in batches. Multiple technicians work to process multiple samples at the same time. A Certifying Scientist who did not perform or observe the testing is not going to be able to guarantee every step of the process was error-free. For more in-depth discussion of these problems, please see: http://nccriminallaw.sog.unc.edu/the-nc-supreme-courts-recent-substitute-analyst-cases/

Does NMS have different procedures from the NCSCL?

Some of NMS’s procedures are different. NMS provides quantified results for their toxicology reports, estimating the amount of a substance found in the blood sample and, for a time, NMS witnesses opined about the impairing effects of substances which they found, but NCSCL has advised them not to do this. A Pharmacologist could look at this quantified data and say whether the dosage is commensurate with a therapeutic dosage or not, and even testify to the impairing effects. If the Certifying Scientist intends to give testimony about the impairing effects, per N.C. Gen. Stat. 15A-903 and Rule of Evidence 702, that opinion would need to be disclosed in their report and they would need to have pharmacological training to support that testimony.

The NMS Labs also uses a different sort of spectrometer to analyze their samples. The NCSCL uses a Gas Chromatography Mass Spectrometer (GCMS), an instrument that passes an ion beam through a gas and detects the energy changes in the substances found in the gas taken from the sample. NMS Labs uses a Liquid Chromatography Mass Spectrometer (LCMS). The NCSCL also uses this instrument to perform some toxicology analysis. These techniques produce the same sort of data and are both considered confirmatory tests, but the procedures and instruments used are quite different.

Does NMS have to turn over their lab packet?

In some cases a 3-4 page summary report is turned over to the defense. This is not the entire lab packet. NMS Labs also produces a “litigation packet” that typically is several hundred pages long. The summary report does not contain sufficient information for counsel to understand what tests were performed and whether they were performed correctly. If the case is within the original jurisdiction of the Superior Court, the rules of discovery apply and you would be entitled to the lab packet through discovery. If the case is within the original jurisdiction of the District Court, you can ask the judge to order the prosecution to turn over a copy. If the witness relies on his or her report during testimony and it is not turned over until then, it would be extremely time-consuming for counsel to attempt to review it at that time. In some jurisdictions, the litigation packets are being turned over in District Court prior to trial.

This packet is huge and really hard to understand.

Yes, that does seem to be the way of things. It is hard to imagine that this packet was designed with the purpose of giving the reader easy access to the relevant information. Their reports typically spend a lot of time identifying the presence of many metabolites of a substance. These are just the indicators of the substance being present and metabolized, not additional substances. Additionally, metabolites can be active or inactive, meaning that some metabolites have no impairing effect, and could even indicate a lack of impairment.

If you have any concerns about how a drug is metabolized, or what a drug’s metabolites are, LabCorp has a rather comprehensive guide to the metabolites of Benzodiazepines and Opiates.

If you need a starting point for the effects of a certain substance on a human who has ingested it, the NHSTA has Drug and Human Performance Fact Sheets on 16 different commonly used drugs — including cocaine, cannabis, methadone, Valium and Ambien — prepared by pharmacologists to describe how average humans are impacted by drug usage. These models are based on normal, healthy humans, and any increased tolerances or other reasons why the model does not fit your client should be discussed with an expert.

It is highly advisable that, at this time, that you get an expert to review the data with you after you get the packet. One easy to spot problem is if the data representation where the x-axis is time and the y-axis is signal intensity, the peaks do not touch the bottom of the graph, that is a pretty serious problem. Since NMS provides the quantity of the substance, if they cannot accurately tell where the substance they are analyzing begins or ends, they cannot have much accuracy on the quantity they are saying is present.

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Free Workshop: Forensic Technology and the Impact on Frye and Daubert Standards

The Forensic Technology Center of Excellence (FTCoE) at RTI International, Duquesne University, and the Allegheny County Medical Examiner’s Office are holding a workshop in Pittsburgh, PA on August 9th & 10th, 2016. The workshop will focus on information a likely to show up in cases involving forensic evidence, the technologies behind that evidence, and the impact of the Frye and Daubert standards for admissibility of expert testimony.

The legal profession strives to have a better knowledge of the scientific principles and technologies employed in forensic evidence analysis. Forensic practitioners and scientists have been actively developing methodologies and innovative technologies to analyze evidence. In turn, professionals in the criminal justice system who are responsible for making legal decisions must have an understanding of these technologies and the impact of Frye and Daubert standards on the admissibility of testimony about these technologies.

Criminal court judges, prosecuting and defense attorneys, and legal academicians are encouraged to apply. Space is limited to 25 attendees and nominations are required. The deadline for nominations has been extended to July 22. The FTCoE will provide workshop registration, airfare, lodging, and per diem expenses for all attendees. A Certificate of Completion will be provided to document two days of continuing education.

For more information, please visit the Forensic Technology Center of Excellence website for the event.

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