DNA TYPING OF BLOODSTAIN: A CASEWORK OF MORTAL CRASH

Abstract

Since 1997 the analysis of DNA recovered from handled objects, or trace DNA has become routine and is frequently demanded from crime scene examination. However, this analysis often produces unpredictable results. The factor affecting the recovery of full profiles are numerous, and as demonstrated in casework and research, retrieving useable profiles from trace DNA exhibits is not guaranteed. There are numerous factors that affect the rate of recovery of full profiles, such as the ability of the individual to shed cells, the substrate surface, the time of contact and delay until analysis, and the environment. In addition to these external conditions, there are many varying methods used to collect, extract and analyse the samples, each with particular benefits and limitations. We report a casework of mortal crash in which evidence collected at the crime scene was found to be hairs and many bloodstain in different substrate of the two part of the car; but also evidence collected 15 months later submitted to environment stress. The purpose of the analysis was to identify the driver between two suspects. Into the car at the crash moment were two gays and two females: one woman died. The use of DNA profiles was combined to morphological aspect and localization of bloodstain; in such way the power in the analysis of biological evidence identification provides a high level of identification.