An Illustration of Particle Combination Analysis

What could have happened, but didn’t

Imagine what could have happend but didn't:

A vehicle stopped somewhere near the southern US border is determined to contain a combination of illegal immigrants, weapons and drugs.  A quick wipe of dusts is taken from the clothing, weapons, and drug packaging.  A rapid, inexpensive analysis of the dust results in a distinct particle profile that is compared against a database of similar profiles collected from previous cases, seizures, arrests and detainees. Within hours the investigators know:

Whether an established route was used to cross the border, and which one
Whether a new route (such as a recently-dug tunnel) was used, along with details on how to locate it: a narrow area within which to search, a description of the immediate environment (rural, agricultural, developed), and nearby landmarks such as specific types of vegetation, rock outcroppings, or commercial activity
Whether there are links between this case and the particle profiles taken from other cases, arrests and seizures

Comparable information is provided to Mexican law enforcement about the origin, within Mexico, of the vehicle, immigrants and contraband.

The information from this case is entered into the database aiding all future investigations, including those focused on specific seizures or incidents, as well as the comprehensive tracking of changes and flow across different routes. With hundreds of daily stops and seizures, the database grows rapidly and becomes a major contributor to investigations across programs in DEA, Homeland Security, Immigration and Customs, ATF, and affected local jurisdictions.

A victim of human trafficking escapes and shows up at a clinic in Baltimore
She doesn’t speak English and has no idea where she has been taken or held. Wipes of dusts from her personal belongings are used to produce particle profiles that provide links to other individuals and cases, and to identified or suspected human trafficking sites.

Dust from the clothing she wears provides information about where she has been most recently held, narrowing the search to less than 10% of the surrounding area, and giving descriptions of  the immediate environment, with landmarks to help investigators locate the specific site within this area.

The information from this case is entered into a database used to combat human trafficking networks all over the US.  Similar databases use particle profiles as a means to link cases and investigate illegal distribution networks ranging from counterfeit and black-market pharmaceuticals, to stolen automobiles, to unlicensed weapons sales.

At the state or local level, police seize a cache of weapons or drugs. A wipe of dusts produces a particle profile which is compared against the locally maintained database.  Within hours links are established to other seizures and cases, narrowing the source to one of 8 areas within the jurisdiction. Alternatively, an entirely new source is recognized, or one of several identified sources from other jurisdictions.


Overseas, recovered bombs and IEDs are wiped in several interior locations enabling rapid, inexpensive conclusions such as: The detonator was made in this area. This is a new source of explosives. This is from a specific assembly site we’re trying to find, with new investigative information to help find the site.



None of these things happened, but they could have - and more importantly they should have.

These capabilities exist. The US Government funded the development of this capability and it has made significant contributions to a number of cases where other methods either failed or were not found to be practical in the specific circumstances. Details of how this capability works and demonstrated results have been presented at scientific meetings, published in peer-reviewed scientific journals, and attested to by senior government scientists and by program managers who have used it on difficult cases. The capability is available to government agencies, is not expensive to implement, and uses existing staff and equipment.

This is a potential game-changer.  So why isn’t it routinely used as part of ongoing programs?

There are two reasons: First, the capability is a recent development and some common misconceptions lead to mistaken conclusions that the capability is not practical or that it is already being used. Second and most importantly: implementation, while not particularly difficult or expensive, requires direct leadership and coordination by a Program Manager.

There are five important things a Program Manager should know about Particle Combination Analysis to understand the potential and what he or she needs to do to take advantage of it.