Detecting Latent Prints on Stone and Other Difficult Porous Surfaces via Indanedione/Zinc Chloride and Laser

Lasers and alternate light sources have been recognized as effective tools for latent print detection for over three decades.Luminescence often increases friction ridge contrast to reveal impressions otherwise undetectable.Indanedione/zinc chloride excited by a forensic light source is widely recognized as an effective process for developing latent prints on porous surfaces.This study was designed to evaluate the use of a combination of luminescence excitation and indanedione with zinc chloride to detect latent prints on stones,bricks,and similar difficult porous surfaces.The wavelengths evaluated included 400 nm(violet),447 nm(blue),532 nm(green),and 645 nm(red).Latent prints were deposited on a variety of porous surfaces including bricks,cement stones,wood,and cotton fabric,all commonly encountered at crime scenes in China.The surfaces were examined using white light(light‑emitting diode flashlight)and laser light sources separately,both before and after treatment with indanedione/zinc chloride.The goal of this study was to evaluate various light sources for their effectiveness in detecting impressions developed by indanedione/zinc chloride on difficult porous surfaces.Results indicated that latent prints on some brick and cement stone surfaces may be effectively detected using 532 nm laser excitation after indanedione/zinc chloride processing.

The Shifting Landscape of Latent Print Testimony:An American Perspective

Friction ridge comparison testimony in the United States has long been characterized by speaking in absolutes:fingerprints are unique,the Analysis,Comparison,Evaluation,and Verification methodology has a zero-error rate,and the testimony presented by the expert should be regarded as an incontrovertible fact.Once the National Research Council released their watershed report in 2009,questioning and criticizing these clear overstatements of the strength of the evidence,many commentators and professional organizations recommended that the friction ridge community rethink the way their evidence was presented in reports and in court.Yet,change has been slow to come.While some agencies have begun a shift in the way they present their findings,many others still testify the same way they always have.This paper presents the historical context of where American friction ridge testimony has been,lays out the arguments for why it needs to change,describes some recent efforts to improve,and highlights some likely directions for the future of friction ridge reporting and testimony in the United States.

Sex Determination Using Cheiloscopy and Mandibular Canine Index as a Tool in Forensic Dentistry

Identification of a person's individuality and sex determination are important for legal as well as identification purposes.The aim of the present study was to check the reliability of cheiloscopy and mandibular canine index(MCI)in the detennination of sex in an individual.The aim of this study is to analyze difierent lip patterns reproduced by the natural dye(vermilion)and lysochrome(Sudan Black Ⅱ)dyes and to compare the MCI in males and females for the determination of sex and to check the reliability of cheiloscopy and MCI for the same.Latent lip prints were developed using natural dye(vermilion)and lysochrome(Sudan Black Ⅱ)dyes and their patterns categorized according to Tsuchihashi's classification.MCI were calculated.Analysis of the two was performed.According to discriminant functional analysis,percentage accuracy for cheiloscopy in the determination of sex was found to be 55%while for MCI,the same value was 85%.Natural dye(vermilion)was found as an efficient dye compared to lysochrome(Sudan Black Ⅱ)dyes for the development of latent lip prints.Both the dyes showed Type Ⅰ lip print pattern to be common in males and females.Furthermore,all the parameters in MCI were found to be significant in the determination of sex in an individual.The results of the present study revealed MCI to be more reliable in the determination of sex than cheiloscopy.