The contribution of DNA databases for stored sexual crimes evidences in the central of Brazil.

Accumulation of sexual assault evidences unsubmitted to forensic DNA testing raises concern and it favors low rates of sexual crimes resolution. However, with the advent of DNA databases, these evidences have provided valuable information for investigations. In Brazil, the use of DNA databases is recent and few studies assessed their contribution to criminal resolution. In this regard, this study aimed to evaluate the potential of the DNA Database of Goias State, Central Brazil (BPG-SPTC/GO) in the resolution of sexual crimes without suspects through the insertion of profiles obtained from stored untested evidences collected between 2004 and 2018. Samples were submitted to DNA extraction by differential lysis, followed by the amplification of STR autosomal markers, capillary electrophoresis analysis in the ABI 3500 genetic analyzer and insertion in the BPG-SPTC/GO using CODIS 7 software. The rate of eligible samples for insertion and rates related to the obtained matches were evaluated. Statistical analyses were performed with Epi Info ™ v.7 and BioEstat 5.0 software. A total of 275 samples were submitted to DNA testing, 202 out of them (73.5%) presented eligible profiles for insertion. A total of 176 (64%; 176/202) were inserted, one crime scene profile from each case. Overall, 60 hits were generated, all series sexual matches; a higher prevalence of forensic hits was detected (81.7%; 49/60) and a total of 32 criminal investigations were assisted (18.2%; 32/176). As the use of DNA databases in Brazil is recent and Brazilian criminal law has stringent requirements, our results reinforce that the use of DNA databases for stored sexual crimes evidences is a feasible forensic tool and that the increasing of the number of both types of profiles in DNA databases, evidences and criminals, causes positive reflects on the number of matches generated. However, further studies are necessary to evaluate if this effectiveness reflects positively on conviction rates of sexual crimes.

Genetics and molecular biology: a literature review of forensic dentistry application

Forensic expertise methodology normally used in different criminal investigation and forensic medicine field such as blood type, anthropologic analysis and forensic dentistry (dental records, X-rays, bite marks, among others) solved and will continue solving many crimes. Those methods will continue estimating age of several people. Nevertheless, since the development of genetics and molecular biology there were an increase in number and quality of solved cases. The present work points out the importance to associate certain forensic biology areas to traditional investigation methods in human identification, especially with forensic dentistry. It also shows that in some situations, teeth are an important source to genetic analysis and molecular studies. After a scientific literature review it was concluded that it is mandatory that those in forensic investigations acquire knowledge in forensic genetics in order to apply with traditional investigation techniques, this fact would produce an increase of information to Justice.