A novel approach for sex determination using palmar tri-radii: A pilot study

Palmprints are often encountered on the scene of crime. It can play a key role in sex determination (male or female), which may help in the process of elimination and hence in narrowing down the suspect pool during forensic investigation. In the present study, 300 bilateral palmprints collected from 150 healthy consenting adults (75 males and 75 females) belonging to heterogeneous population of central India were examined. The distance between the palmar tri-radii (deltas) 'a', 'b', 'c', 'd' to the axial tri-radius 't' were studied individually as well as combined. Applying t-test, the results were found to be statistically significant (p < 0.05). Probability densities for men and women derived from the frequency distribution were used to calculate the likelihood ratio and posterior probabilities of sex designation for the given combined abcd-t distance for subjects using Baye's theorem. For left as well as right palmprint, a combined distance of ≤30 cm will have a higher probability of belonging to a female donor (p = 0.99) while, a combined distance of ≥32.5 cm will be more indicative of the print belonging to a male donor (p = 0.99).