Judges and forensic science education: A national survey

Statistics of fingerprint minutiae frequency and distribution based on automatic minutiae detection method

The Daubert case in Philadelphia in 1999 caused a debate about the scientificity of fingerprint evidence. Since then, the current fingerprint identification system has been constantly challenged and questioned. Quantitative identification technology based on the statistics of fingerprint minutiae has become a new research hot spot. In this paper, an automatic detection algorithm is designed to achieve automatic classification of fingerprint minutiae using the deep convolution neural network YOLOv5 model. Then the occurrence frequencies of minutiae are statistically evaluated in 619,297 fingerprint images. The results show that the frequency ranges (unit%) of six types of minutiae per finger are ridge endings [68.49, 70.81], bifurcations [26.37, 27.26], independent ridges [1.533, 1.626], spurs [1.129, 1.198], lakes [0.4588, 0.4963], crossovers [0.3034, 0.3256]. The results also show that there are differences in the distribution frequency of the six types of minutiae in the ten finger positions ( thumb, middle, ring, index and little finger of the left and right hand) and in the four finger patterns ( arch, left loop, right loop and whorl). From the quantitative point of view of fingerprint identification, this paper calculates the number and frequency ranges of six types of minutiae, distinguishes the evaluation value of each type of minutiae, and provides the basic data support for establishing a probability model of fingerprint identification in the future.

Surveying practicing firearm examiners

A sample (n = 79) of practicing firearm and toolmark examiners was queried about casework as well as their views about the potential role that statistics might play in future firearm examinations and expert witness testimony. Principal findings include: The modal response for time spent conducting bullet examinations is 2–4 hours, and the modal response for cartridge casings is 1–2 hours. The average participant (median) makes an identification in 65% of casework, makes an elimination in 12% of casework, and reports that the examination was inconclusive in 20% of casework calls. The vast majority of examiners work at laboratories that permit eliminations when class characteristics agree. The reported industry-wide false positive error rate is 1%, though very few participants could name a study or give a citation for their reported estimate. Qualitative responses about the potential role of statistics were mixed.