Departamento de Zoología y Antropologı´a Física, University of Alcala, Alcalá de Henares, Spain.
Forensic Sci Int. 2011 May 20;208(1-3):79-90. doi: 10.1016/j.forsciint.2010.11.006. Epub 2010 Dec 10.
One of the fundamental aspects of the process of identification through fingerprints is the comparison of the minutiae between the fingermark obtained at the scene of the crime and the suspect's corresponding finger. There is no scientific basis in this process that allows the use of numerical standards, such as those kept in different countries, to obtain the identification. The recent mistakes made in the field of dactyloscopy, together with the growing rigor and scrutiny that forensic evidence undergoes in the legislative and scientific areas, have resulted in the need to reconsider some of the basic principles that support this discipline. A probabilistic estimation of the evidential value is especially necessary; therefore, it is indispensable to know and quantify the variability of the features used in the identification process. The sample studied for this research was obtained from 100 Caucasian men and 100 Caucasian women from the Spanish population, which amounts to a total of 2000 fingerprints. The different types of minutiae were located, identified, and quantified visually on the fingerprint, in four sectors, and inside and outside of a circle, whose radius cut, perpendicularly, fifteen ridges starting from the center cut of the axes that defined the sectors. According to the results obtained in this study, through dactyloscopic identification, the weight of the evidence of a minutia, such as the ridge endings, with frequencies between 55% and 65%, according to the area and gender evaluated, cannot be the same as that of a bifurcation or convergence, with frequencies of 13-18% or those of other minutiae that show frequencies lower than 3%. The significant differences found in the topological distribution of the endings, bifurcations, and convergences show the need to take into account, for its demonstrational value, the finger area in which they are evaluated. The significant association observed between the types of minutiae and the different fingers revealed a greater frequency of endings on the thumb and index fingers, and bifurcations and convergences on the middle, ring, and little fingers.
指纹识别过程的一个基本方面是比较犯罪现场获得的指纹痕迹与嫌疑人相应手指的细节特征。在这个过程中，没有科学依据可以使用数字标准，例如不同国家保存的标准，来进行识别。最近在指纹学领域出现的错误，以及法医证据在立法和科学领域受到的日益严格和审查，使得有必要重新考虑支持这一学科的一些基本原则。特别是需要对证据价值进行概率估计；因此，了解和量化识别过程中使用的特征的可变性是必不可少的。这项研究的样本是从西班牙人口中的 100 名白种男性和 100 名白种女性中获得的，共计 2000 个指纹。在四个扇区以及一个圆的内部和外部，通过视觉定位、识别和量化指纹上的不同类型的细节特征，该圆的半径垂直于从定义扇区的轴线的中心切割处开始的 15 条脊线切割。根据本研究的结果，通过指纹识别，频率在 55%至 65%之间的脊结束等细节特征的证据权重，根据评估的区域和性别，不能与频率为 13-18%的分叉或收敛，以及其他频率低于 3%的细节特征的证据权重相同。在结束、分叉和收敛的拓扑分布中发现的显著差异表明，需要考虑到其论证价值，对评估的手指区域进行考虑。观察到的细节特征类型与不同手指之间的显著关联表明，在拇指和食指上结束的频率更高，而在中指、环指和小指上分叉和收敛的频率更高。
