Identification of a criminal by DNA typing in a rape case in Rio de Janeiro, Brazil.

CONTEXT Human DNA identification is a powerful tool for paternity cases as well as for criminal investigation, in which biological evidence is typed after collection from crime scenes and for the identification of human remains. OBJECTIVE Identification of a criminal in a rape case with 4 suspects using STR and VNTR DNA analysis. TYPE OF STUDY Forensic DNA analysis. SETTING DNA Diagnostic Laboratory, Universidade Estadual do Rio de Janeiro, Brazil. PARTICIPANTS Blood from 4 suspects and the victim, and skin from the fetus. PROCEDURES Polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP). RESULTS Three of the suspects were excluded and one of them was identified as the biological father of the fetus after typing with CTT and FFv Multiplexes. Complementary DNA typing at 3 VNTR loci was also carried out. CONCLUSIONS After typing four suspects using 6 STR loci, one of them was identified as the biological father of the fetus. In order to significantly enhance the Combined Paternity Index (PI), complementary DNA typing in 3 VNTR loci was carried out. The included suspect was found to be the biological father with a PI of 412,860 (Probability of Paternity: 99.9997%).