Dust prints - plastic or patent?

[josher89]

Dust prints are generally a removal of a layer of dust on a surface. The dust has three-dimensional properties. Does this mean that a dust print would be (should be) classified as a patent print or a plastic print?

Just a small debate in my office...

[Dr. Borracho]

If we are measuring the surface relief between ridges and furrows in microns, then I imagine that the residue of a sweat print would have three dimensions, too.

I would suggest that, in a plastic print, the ridges & furrows modify the substrate. I think you could argue that, in a dust print, the substrate is not modified by the ridges & furrows. Unless you define the dust as the substrate.

[Boyd Baumgartner]

Obviously, they're elimination prints, because the dust has been eliminated in the process of deposition.

Alternatively you could argue they don't exist because they're not mentioned in the SWGFAST terminology document.

[Ernie Hamm]

The designation of patent/latent/plastic on dust prints has previously been stated in the following article:

IAFIS - Two Murdered Schoolteachers and a Single Patent Print in Dust”, Gary Krohn, JFI 51:6(2001)

I believe that the term plastic print is intended for impressions in a malleable substance or surface.

[Shane Turnidge]

In Canada they are referred to as "take away prints".
As for the 3-D nature of the prints, you could say powdered prints are 3-D as well. I'll defer to the wisdom of Ernie and agree that plastic prints are prints in a malleable or viscous substance.

Shane Turnidge

[Ernie Hamm]

Shane,

Thanks for the "wisdom" tag, but it was BASIC latent print knowledge, probably learned from first IAS lessons. (Let some of the current practitioners wonder about that reference)

Your take-away label is similar to a term I used when I was doing some data collection on track evidence and needed a descriptive term. I settled on "subtractive" track to describe track evidence as a result of footwear or tire contact removing substance from a substrate as opposed to an "additive" track when features were added to the substrate by contact.

Ernie