Category Archives: Fingerprints

“Forensics on Trial” program on NOVA

NOVA (PBS) aired a program called “Forensics on Trial” on October 17, 2012, examining the crisis facing crime labs in the U.S which lack central oversight, employ few scientific standards, and have poor regulation of examiners. The program investigates how the use of fingerprint, bite mark, ballistics, toolmark, and hair analysis evidence has led to wrongful convictions. The program will examine the 2004 Madrid bombing case in which a so-called fingerprint match was used to arrest an innocent man. The fingerprint was later matched to another suspect.  The program will also discuss how mishandling of forensic evidence impacts the criminal justice system, from wrongful convictions to the O.J. Simpson trial.  You can read about the details of the program here.

More information is also available on the NOVA website where the program can be viewed online.

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Free at Last! Willie Grimes Exonerated by 3-Judge Panel

A 3-judge panel found Willie Grimes innocent after thirty-minutes of deliberation on Friday.  Grimes had been sentenced to life in prison in 1987 after being convicted of two counts of first degree rape and one count of second degree kidnapping.  He was paroled in May of this year after serving twenty-four years in prison.

Grimes’s case was heard in April by the Innocence Inquiry Commission, which unanimously agreed that enough evidence existed to refer his case to the 3-judge panel.  The rape kit and hairs found at the scene had been lost and were unable to be utilized in exonerating Grimes.  However, a fingerprint on a banana, which the victim had claimed her attacker may have touched, was analyzed and confirmed as belonging to someone other than Grimes. Grimes was represented by attorneys Chris Mumma, director of the North Carolina Center on Actual Innocence, and Robert Campbell of Hickory.

You can read more here, here, or here.

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NIJ Has Made Available New Forensic Technical Reports

The National Institute of Justice has published several reports on novel techniques that are being investigated in order to improve forensic analysis. Take a look at the reports below to learn about some of the latest techniques that are being developed and to get a forecast of what techniques you may see coming soon to a forensic lab near you!

Application of Machine Learning to Toolmarks: Statistically Based Methods for Impression Pattern Comparisons (pdf, 99 pages)

Researchers created a database of 3D striation and impression patterns on Glock fired cartridge cases, screwdriver and chisel striation patterns. They attempted to objectively associate the toolmarks with the tools that created them using principal component analysis, canonical variate analysis, and support vector machine methodology. Researchers were able to estimate an error rate for toolmark identification using these techniques and a confidence level was assigned. Researchers suggest that this methodology is a useful means of gauging the quality of a toolmark “match.”

Application of Raman Spectroscopy for an Easy-to-Use, on-Field, Rapid, Nondestructive, Confirmatory Identification of Body Fluids (pdf, 80 pages)

Research indicates that new nondestructive, confirmatory testing could identify bodily fluids, including dried fluids, with a near 100% accuracy rate using a Raman microscope equipped with advanced statistics for rapid mapping of pure bodily fluids. The research further proposes that mixed samples can be identified if the samples are not completely mixed. This nondestructive testing, if adopted in the future, could help in the preservation of crucial DNA evidence. It also offers a heightened level of confidence in the results obtained due to its confirmatory nature and level of accuracy.

Establishing the Quantitative Basis for Sufficiency Thresholds and Metrics for Friction Ridge Pattern Detail and the Foundation for a Standard (pdf, 53 pages)

Motivated by both the Daubert ruling and the findings of the National Academy of Sciences, Strengthening Forensic Science in the United States: a Path Forward (2009), researchers from multiple disciplines collaborated to develop a scientific foundation for fingerprint image quality, with a focus on latent prints.  Researchers followed an experimental approach and then performed statistical validation of their results. Their research yielded several noteworthy results, most salient being detection of unique features that can assist fingerprint examiners in drawing statistical likelihoods of a given feature. This project bolsters claims that existing methods of analysis are more of an art than a science and therefore more susceptible to human error.

Filling a Critical Need by Establishing a Fully Functioning, CODIS Dedicated Laboratory (pdf, 101 pages)

The state of Wyoming requires maintenance of a database of offender samples which historically have been processed via outsourcing to private agencies.  Through funding from both the NIJ and Wyoming State legislature, Wyoming has established their own CODIS lab to process offender samples for entry into CODIS. Currently, samples processed through the lab pass through to CODIS at a 95% success rate. Through creation of the state-run lab, sample processing time has been cut from more than two years to less than sixty days.

Implementation of a DNA Triage and Analysis System Dedicated to Increasing the Throughput of High Volume Crimes in a Forensic Laboratory (pdf, 133 pages)

Through the efforts of both the Orange County California crime lab and the Orange County District Attorney’s office, the crime lab implemented a team-oriented approach to processing DNA from property crimes. The approach employed a highly automated DNA processing method that the crime lab anticipated would free up time from the processing of property crimes, which are extremely high in volume, to devote to dealing with violent crimes. As anticipated, the new handling method decreased the turn around time on both property and violent crimes.

Taq Mutants Engineered for Forensics (pdf, 44 pages)

Researchers used novel genetically-engineered enzymes and a new protocol for DNA analysis to attempt to reduce false negative results and improve the efficiency of DNA testing. These novel enzymes and new protocol would work better with forensic samples that contain residual blood, soil, or other substances that inhibit forensic DNA analysis. Researchers found that their technique outperformed the techniques currently used in forensic DNA analysis.

Use of Scanning Electron Microscopy/Energy Dispersive Spectroscopy (SEM/EDS) Methods for the Analysis of Small Particles Adhering to Carpet Fiber Surfaces as a Means to Test Associations of Trace Evidence in a Way that is Independent of Manufactured Characteristics (pdf, 77 pages)

Typically, very small particles (VSP) are ignored by forensic science. However, researchers have made the first steps towards developing a method for collecting and analyzing VSP as part of trace evidence. Researchers have successfully collected VSP from carpet fibers and demonstrated the difference between carpet fibers themselves and the VSP adhering to them. Researchers urge that VSP can prove useful in the area of trace evidence by comparing VSP from crime scenes or suspects to any items of physical evidence.

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Impression & Pattern Evidence Symposium – Online today!

The Impression & Pattern Evidence Symposium is taking place today through Thursday, August 9, 2012. The live program, sponsored by the National Institute of Justice (NIJ) Office of Justice Programs and the Federal Bureau of Investigation (FBI) Laboratory Division, is being streamed online here.

The agenda is available here. Topics include the latest developments and challenges to fingerprint, firearm, document, tiremark, bloodstain pattern and other types of pattern and impression evidence as well as context bias, calculation of error rate, documenting through bench notes, outsourcing lab analysis, and the way to present degree of certainty.

The entire program is available for free online streaming, so sign up and watch the sessions that are of interest to you!

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Crime scene forensics: How does it work?

BBC News has posted a series of videos explaining how forensic tests are performed in crime labs on their Crime scene forensics: How does it work website. These short videos demonstrate various techniques including fingerprint comparisons, use of ninhydrin and superglue fuming (cyanoacrylate) to locate latent print evidence, firearm and projectile comparisons, and examination of pieces of evidence using specialized light sources. The website also contains a limited description of forensic DNA analysis.

The demonstration of these lab techniques should help attorneys understand the function and the limitations of such tests. Viewing the video demonstrations while reading the State Crime Lab technical procedures for latent evidence examination may help attorneys visualize the tests that the technical procedures describe.

Another section of the website provides a 360° crime scene demonstration, which gives a basic description of the phases of evidence collection, the techniques used to preserve evidence, and the roles of crime scene technicians.

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