Forensic identification of two murderers by DNA multi-reverse parental analysis

Abstract In this paper, we present a murder case committed by three men in a small town in northern Italy in which two of the murderers were identified by means of a multi-reverse parental analysis approach. Four different complete male profiles for 17 STRs were obtained from the bloodstains and other evidence collected at the crime scene, one of which belonged to the victim. Two of the three unknown profiles revealed similar characteristics for many alleles/loci tested, which could be explained by a possible parental linkage. The investigators focused their attention on some families in gypsy communities with records of robberies. All donors were excluded except for two individuals whose profiles were very similar to the two unknown DNA profiles obtained from the crime scene. We then decided to type the close relatives of these two individuals. Among the relatives typed, four of them appeared to belong to the parents of the two unknown men involved in the murder. As a consequence, one murderer was arrested after a few weeks, the other more than 2 years.