Five things

What every program manager should know about Particle Combination Analysis


Particle Combination Analysis is a new approach that uses co-occurring particles to test alternative attribution hypotheses. Simply put, Particle Combination Analysis exploits the particles in dusts, which are ubiquitous and in infinitely varying combinations, to solve a wide range of problems with varying case specifics. This approach can provide a game-changing capability to forensic investigators, working alongside existing investigative methods and using portions of evidence that are typically discarded or ignored. The approach utilizes existing staff and laboratory resources in a fundamentally different way; it does not require major investments in training, equipment, or retention of outside experts. It does require a change to the way existing resources are used.

If you are a Program Manager involved with either...

Determining where people or objects have come from, such as:
Rapidly locating the source of health hazards such as contaminated products
Verifying the origin of shipments entering the country
Determining the origin or manufacturing site of bombs or their components


Determining links associating multiple people, activities or pieces of evidence, such as:
Does a bomb recovered in Canada have components from the same supplier used by the Boston Marathon bombers?
Were guns used in a highjacking stored in the same location as drugs recovered on another case?
Working to identify and defeat networks of criminal and terrorist activities

There is a very good chance recent advances in the application of Particle Combination Analysis can be a game-changer, and that your organization is not taking advantage of these advances.

There are five important points you should be aware of as a Program Manager.

Hundreds of these particles would fit on a cross section of a human hair. They are the result of the object’s unique history of exposure. Routinely, such dusts contain a tremendous variety of particles from plants, soils, and human activities. The large numbers of particles and their infinite combinations mean that combinations of these particles can provide particle profiles that can be used to determine associations with, and differentiations from the particle profiles of other objects or locations. Additionally, by analyzing the exposures necessary to create a specific combination, possible origins can be narrowed down and nearby landmarks and environments can be determined. This makes search efforts materially more efficient and provides a means to test and confirm the specific origin.

Particles easily recovered from items:

On virtually any object and within any product:


Analyses of single particle types such as Pollen or Explosives are already widely used, employing increasingly sophisticated methods and technology. Most laboratories commonly use instruments such as Raman, FTIR, SEM, and GC/MS to provide valuable information (just as measures of temperature, humidity and wind speed are common measurements used by meteorologists). However the combination of a suite of such measurements into an informative and predictive tool (comparable to the weather maps we watch on TV) is fundamentally different from increasingly more precise measurements of temperature or wind speed.

This distinction is explicitly detailed and illustrated in the March 2013 issue of Forensic Science Review, following a comprehensive review of scientific literature, extensive interaction with national government and contract laboratories, and discussions with senior program managers in the DoD, Homeland Defense, FDA, Intelligence Agencies, and Law Enforcement. The review details widespread use of limited single-particle approaches and restricted method analyses, along with the virtually unimplemented potential of using particle combinations to achieve meaningful program solutions.

Analysis of individual particle types can be very effective for specific questions or problems involving a specific drug, explosive, residue or chemical present, such as:

Was a person in proximity to ammonium nitrate that is used in making bombs?
Does soil on this person or evidence come from this specific location?
Do the chemical properties of one material match those of another?

In contrast, analysis of particle combinations can address broader questions such as:

Was this person involved in any bomb making activity?
Where should we focus our search for a person, hazard or threat, and what environment and nearby characteristics should we be looking for?
Can we link or disassociate this object from any of a large group of other objects which may or may not share common materials?

During development and testing as an outsourced, expert-dependent capability, Particle Combination Analysis has been repeatedly demonstrated to be effective at:

  • Inferring locations - country, city, specific building Rapidly narrowing a search so investigators can focus activity on a small area
  • Identifying characteristics of the nearby environment that will aid in a search - vegetation, commercial activity, proximity to roads and bodies of water, etc.
  • Inferring the origins and assembly sites of items of interest
  • Identifying particle combination profiles from seized weapons, explosives and contraband that readily identify links between different crimes, events and people 
  • Such case results have repeatedly been characterized by senior officials as, ‘Among the most actionable intelligence we have received on this project.’

Particle Combination Analysis is no longer experimental, expert-dependent, or expensive. The processes have been developed, tested and proven during extensive government sponsored research. Implementation does not require major investments in training, equipment or retention of outside experts. In most cases it can be performed in existing laboratories, without major retooling of processes, using existing equipment and staff. Furthermore, it does not interfere with existing laboratory or investigative processes. It works alongside them using portions of the evidence that are typically discarded or ignored.

There is a modest amount of planning, training and implementation. These can be phased in with measurable contributions within a very short time, and dramatic impact in a matter of months.


This is not a plug and play capability like purchasing a new instrument or software package. Efforts to task lab managers or investigators with adding a Particle Combination Analysis capability have been consistently unsuccessful. Although implementation is not costly or difficult, it does require some changes in approach, coordination, and format of tasking and reporting. These changes typically cross some traditional intra-organizational boundaries. These are not major changes if coordinated at the Program Manager level, but have repeatedly proven insurmountable without such coordination.

The difference between the relatively minor investment in vision, coordination and effort needed to add this as an in-house program capability, and the potential to make significant contributions to a broad range of efforts, is too significant to leave it as an expensive, outsourced option to be called in only on high profile cases.

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