Case report of a homicide resolved 15 years later: The robustness of Chelex extraction

DNA typing techniques is one of the most advanced tools for human identification. During the last 10 years, a great number of methods for DNA extraction and analysis have been introduced to forensic genetic, with considerable success but also with considerable controversy. The success and validation of a criminal investigation are very closely related to the process used for obtaining and preserving biological evidence.We report the strategy that we employed to analyze evidences belonging to a homicide happened in Brescia (Italy) in 1992, not resolved at that time, with the forensic genetic analysis. After 16 years the analysis were conducted on DNA samples extracted with Chelex maintained at −80 °C, bloodstain, and biological specimens of perpetrators. Standard autosomal and Y-chromosome STR analysis identified the persons involved and victim's profiles. This case is of interest as a demonstration of a more successful application of DNA typing in well conserved DNA samples than in bloodstains kept in the Court Office.