Soil complexity, heterogeneity and transferability make it valuable in forensic 
investigations to help obtain clues as to the origin of an unknown sample, or to 
compare samples from a suspect or object with samples collected at a crime 
scene. In a few countries, soil analysis is used in matters from site 
verification to estimates of time after death. However, up to date the 
application or use of soil information in criminal investigations has been 
limited. In particular, comparing bacterial communities in soil samples could be 
a useful tool for forensic science. To evaluate the relevance of this approach, 
a blind test was performed to determine the origin of two questioned samples 
(one from the mock crime scene and the other from a 50:50 mixture of the crime 
scene and the alibi site) compared to three control samples (soil samples from 
the crime scene, from a context site 25m away from the crime scene and from the 
alibi site which was the suspect's home). Two biological methods were used, 
Ribosomal Intergenic Spacer Analysis (RISA), and 16S rRNA gene sequencing with 
Illumina Miseq, to evaluate the discriminating power of soil bacterial 
communities. Both techniques discriminated well between soils from a single 
source, but a combination of both techniques was necessary to show that the 
origin was a mixture of soils. This study illustrates the potential of applying 
microbial ecology methodologies in soil as an evaluative forensic tool.