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

As submitted by the proposer: The ultimate goal of trace forensic evidence in a criminal investigation is to identify the people, places and things involved in the commission of the crime. The reality is that, with most types of non-biological trace evidence, association (however strong) rather than positive identification is a more likely outcome. A commonly found trace material that does not appear to be widely analyzed in operational crime labs at this time is household dust. This is unfortunate since the potential for identification rather than merely association with this type of evidence is a realistic possibility. Dust bunnies (i.e. dust balls) appear to be a unique entangled conglomeration of fibers containing a variety of inorganic and organic particulates from the immediate environment that are formed over a period of time due to air flow and that accumulate inside rooms (inside homes or the workplace), vehicles (e.g. trunk) or even in some outdoor locations. They can be transferred onto, for example, the clothing of a body that has been dragged across the floor prior to the body being taken away and deposited elsewhere. Thus, in principle, if one or more dust bunnies are found associated with a crime it should be possible to positively identify the room from which it originated. The hypothesis of this proposal is that, specifically by conjoining DNA and trace evidence methodologies, it might be feasible to identify not only a particular room that might be the location of a crime scene but also to identify both habitual and recent occupiers of the room. The assembled research team, comprising experts in both microscopic trace evidence and DNA analysis, intends to develop new, innovative, state-of-the-art microscopical techniques and DNA methodologies for the collection and identification of human traces in household dust with a view to improving its potential probative value. They will accomplish this objective by: 1) performing microscopical characterization of organic and inorganic material from dust bunnies and loosely adhering contact traces, 2) evaluating sampling methods for the collection of dust bunnies and loosely adhering surface contact traces, 3) determining the presence and amount of human DNA in dust bunnies and loosely adhering contact traces, 4) performing micro-geographical mapping of bio-particles within dust bunnies, 5) developing suitable DNA recovery and typing methods for bio-particles isolated from dust bunnies and loosely adhering contact traces, and 6) analyzing dust within and between rooms within the same dwelling and between different dwellings to ascertain whether such analysis lends support to the proposition that it is feasible to definitely individualize a room and its occupants. In summary the work described here, if successful, will enable investigators to acquire intelligence (i) concerning habitual and transient occupiers of a room and (ii) to assist in identifying the source of dust when encountered as trace evidence.

Note: This project contains a research and/or development component, as defined in applicable law.

nca/ncf