Sequential Processing

[Heidi Fraser]

I have a question about sequential processing. We received in our lab a piece of cardboard with a faint shoeprint on it in dirt. We wanted to process the shoeprint with potassium thiocyanate, but also the cardboard itself with DFO/Ninhydrin to look for prints. What should be the order of events here? Will the DFO/Ninhydrin wash away the shoeprint? Will the potassium thiocyanate block the action of the DFO or ninhydrin?

Does anyone have experience in this area? Any help appreciated.

[gerritvolckeryck]

Try to lift the footwear mark using the electrostatic dustlifting method (for dust impressions). - no known interference with fingerprint development techniques.
Then - if needed - black gelatin lifter (for residue impressions). - might cause background staining with subsequent fingerprint development techniques on paper/cardboard
I don't advise to use potassium thiocyanate. Potassium thiocyanate will basicly react with iron which may be (hardly) present in dirt. Depending on the procedure you choose, water may be present in reagents or rinsing solutions, causing amino acids to dillute, which will render subsequent ninhydrin and DFO treatment inefficient.

More than average skills may be needed to photograph the footwear marks from dust- and gelatine lifters.

Hope this helps.

Gerrit

[antonroland]

Hello

Any news in this?

Mail me if you require ideas about photographing the shoe print. I have done this stuff for many years long before digital and lately with digital kit.

Good luck!