Application of the mathematical statistics method in investigation procedure

Abstract

The probability that lawbreaker is in the circle of k suspicious persons is defined. The probability is treated as random variable, while number of the suspicious is the parameter of distribution. This distribution is of exponential type. Going over to new random variable and using maximum-likelihood method, two new exponential distributions are found. One of them makes a narrower circle of suspicious persons with respect to the initial one, while the other widens it. The numbers of stable as well as unstable evidence points are defined in using analogy with currents in RL and RC electrical circuit. RL circuit corresponds to stable points and RC circuit corresponds to unstable ones. The criterion of assessing unstable points (statements of witnesses) with respect to stable points (forensic experiments) is given. It turns out that translating factor for unstable points lies within interval (0.95 and 0.5).

Definisana je eksponencijalna raspodela verovatnoće da se krivac nađe u krugu od klica. Verovatnoća se tretira kao slučajna varijabla, dok je broj osumnjičenih parametar raspodele. Linearnom raspodelom polazne slučajne varijable na novu slučajnu varijablu, uz primenu metoda maksimalne verodostojnosti, definisane su dve nove eksponencijalne raspodele od kojih jedna sužava broj osumnjičenih a druga ga povećava. Brojevi indicijskih poena definisani su po analogiji sa strujom u električnim kolima. Sigurnim poenima koje daju forenzička istraživanja korespondirano je RL kolo, a nesigurnim koji se dobijaju na osnovu izjava osumnjičenih i izjava svedoka korespondirano je LC kolo. Ustanovljen je kriterijum vrednovanja nesigurnih poena i pokazano je da se faktor pretvaranja nesigurnih poena u sigurne kreće između 0,95 i 0,5.