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Combined Genetic and Micro-Chemical Analysis of Household Dust as a Definitive Trace Identified of a Room and its Occupants

NCJ Number
Date Published
March 2017
11 pages
This study tested the hypothesis that by conjoining DNA and trace-evidence methodologies, it is feasible to identify a particular room that might be the location of a crime.
The study's focus is on "dust bunnies" (dust balls) that are formed in a room over a period of time due to air flow. In addition to rooms, dust bunnies can be found in car trunks or even in some outdoor locations. Dust bunnies are a unique conglomeration of fibers that contain a variety of inorganic and organic particulates from the immediate environment. Items of clothing and other items removed from a crime scene may have crime-scene dust bunnies transferred to them. This study examined whether the items could be traced to the crime scene by showing through genetic and micro-chemical analysis that the transferred dust bunnies match dust bunnies characteristic of the crime scene. The study confirmed the tested hypothesis. It showed that by combining highly discriminatory DNA and micro-chemical trace technologies that are available in most crime labs, items or bodies removed from a crime scene can be traced back to the spot where the crime occurred. The study conducted microscopical characterization of organic and inorganic material from dust bunnies; determined the presence and amount of human DNA in dust bunnies; developed suitable DNA recovery and typing methods for bio-particles isolated from dust bunnies; analyzed dust within and between rooms within the same dwelling and between different dwellings to determine whether support exists for the hypothesis; and developed statistical models capable of assessing the probability of a specific source for a specific dust bunny. 1 figure and 3 references

Date Published: March 1, 2017