Comparison of the columnar-thin-film and vacuum-metal-deposition techniques to develop sebaceous fingermarks on nonporous substrates.

Both the columnar-thin-film (CTF) and the vacuum-metal-deposition (VMD) techniques for visualizing sebaceous fingermarks require the deposition of a material thereon in a vacuum chamber. Despite that similarity, there are many differences between the two techniques. The film deposited with the CTF technique has a columnar morphology, but the film deposited with the VMD technique comprises discrete islands.

Columnar-thin-film-assisted visualization of depleted sebaceous fingermarks on nonporous metals and hard plastics.

A fingermark on a nonporous substrate can be developed by depositing a columnar thin film (CTF) on it, but the CTF technique's sensitivity for low-quality fingermarks is unknown. The optimized CTF and traditional development of several depletion series of sebaceous-loaded fingermarks were compared using a split-print methodology as well as subjective and objective grading schemes, in a limited laboratory trial. CTF development was superior to development with selected traditional techniques on brass, anodized aluminum, black acrylonitrile butadiene styrene (ABS), and white nylon.

Optimized development of sebaceous fingermarks on nonporous substrates with conformal columnar thin films.

A form of physical vapor deposition, called the conformal-evaporated-film-by-rotation (CEFR) method, was optimized for the conformal deposition of columnar thin films (CTFs) on sebaceous fingermarks. Relying on the surface topology of the fingermark, the CTF development technique is different from traditional development techniques. After the optimization of the development conditions, the CTF development technique was found to be superior to traditional development methods on several nonporous substrates: the smooth side of Scotch(®) Multitask, Gorilla(®) , and Scotch(®) Duct tapes; clear and black soft plastics; stained and sealed walnut and cherry woods; partial bloody fingermarks on stainless steel; and discharged cartridge casings.

An objective fingerprint quality-grading system.

The grading of fingerprint quality by fingerprint examiners as currently practised is a subjective process. Therefore, an objective system was devised to remove the subjectivity. The devised grading system is quantitative and uses three separate, easily available, software packages to ultimately identify the portions of a fingerprint that correspond to low-, medium-, and high-quality definitive minutiae as defined on the Universal Latent Workstation of the US Federal Bureau of Investigation.

The evaluation of fatty acid ratios in latent fingermarks by gas chromatography/mass spectrometry (GC/MS) analysis.

Despite advances in DNA, fingermarks remain one the best forms of evidence available. While fingermarks are routinely analyzed in terms of their patterns, it may be possible to obtain additional information in terms of their chemical composition. If successful, a chemical analysis of the constituents of a fingermark may give scientists additional information that may help in the identification of a person.

Solid-state acquisition of fingermark topology using dense columnar thin films.

Various vacuum techniques are employed to develop fingermarks on evidentiary items. In this work, a vacuum was used to deposit columnar thin films (CTFs) on untreated, cyanoacrylate-fumed or dusted fingermarks on a limited selection of nonporous surfaces (microscope glass slides and evidence tape). CTF deposition was not attempted on fingermarks deposited on porous surfaces.

Bioinformatics and human identification in mass fatality incidents: the world trade center disaster.

Victim identification initiatives undertaken in the wake of Mass Fatality Incidents (MFIs) where high-body fragmentation has been sustained are often dependent on DNA typing technologies to complete their mandate. The success of these endeavors is linked to the choice of DNA typing methods and the bioinformatic tools required to make the necessary associations. Several bioinformatic tools were developed to assist with the identification of the victims of the World Trade Center attacks, one of the most complex incidents to date.

Epidemiology. DNA identifications after the 9/11 World Trade Center attack.

The attack on the World Trade Center on 9/11/2001 challenged current approaches to forensic DNA typing methods. The large number of victims and the extreme thermal and physical conditions of the site necessitated special approaches to the DNA-based identification. Because of these and many additional challenges, new procedures were created or modified from routine forensic protocols.

Optimization of a simple, automatable extraction method to recover sufficient DNA from low copy number DNA samples for generation of short tandem repeat profiles.

Aim: To develop an automated, high throughput extraction protocol in order to produce database eligible profiles from fingerprints and other low copy number (LCN) DNA sources.

Methods: Extraction of either purified control DNA or buccal cells, for example, with commercial kits was compared to extraction with a simple digestion buffer and a subsequent concentration and purification. Results were evaluated based on the amount of DNA recovered and the completeness of the DNA profiles produced.

Evaluation of an automated liquid hybridization method for DNA quantitation.

The AluQuant (Promega Corporation) liquid hybridization DNA quantitation method was evaluated on an automated robotic platform (Biomek 2000, Beckman Coulter, Fullerton, CA) for use in forensic PCR-STR systems. DNA from bloodstains and buccal swabs was extracted by three different methods: Chelex, Qiagen and DNA IQ (Promega). Samples were quantitated using both the Quantiblot and the AluQuant systems.

World Trade Center human identification project: experiences with individual body identification cases.

Aim: To present individual body identification efforts, as part of the World Trade Center (WTC) mass disaster identification project.

Methods: More than 500 samples were tested by using polymerase chain reaction (PCR) amplification and short tandem repeat (STR) typing. The extent to which the remains were fragmented and affected by taphonomic factors complicated the identification project.

Characterization of a novel dimorphism in the 5' flanking region of the short tandem repeat (STR) locus, c-fes/fps (FES).

The FES short tandem repeat (STR) locus contains seven to 14 repeats of the tetranucleotide sequence ATTT. A novel 10 base pair dimorphism in the 5' flanking region of the FES locus was characterized in four broad populations: African-American, Hispanic, Caucasian, and Asian. The absence of the 10 base pair sequence, or (-) allele, was closely linked to FES STR alleles with 10 or fewer repeats.