Processing Stained Unfinished wood

[kimba325]

We are trying to find the best method to process a wooden statue that has a dark enough stain that we believe possible prints would not be seen with Ninhydrin processing. The wood is unfinished. Any ideas?

[Steve Everist]

One thought would be to take advantage of a camera like the Fuji IS-Pro UV/IR.

Before doing so, you'd obviously need access to one of these cameras. Then you could shoot images of the statue itself, using the various filters, to see if the darkness of the wood can be dropped.

Then you would want to try it on a test item using your Ninhydrin formula to see how it reflects IR using the filters that drop the dark color of the wood.

Then, assuming you can get a combination that drops the wood color and reflects the Ninhyrdin, you could proceed to process the statue with that recipe of Ninhydrin and use the IS-Pro with the appropriate filter to visualize any latent prints.

We recently acquired an IS-Pro, but have not had the chance to see how it works with Ninhydrin. I have used it on a check with an inked print with a colorful image on the check background. I was able to drop almost all of the background and separate out the intensity of the different inks along with the inked print.

[areitnau]

I have had some success with Indanedione on darker porous surfaces. It is analagous to DFO, however, in my experience it tends to fluoresce better than DFO. It can still be followed by Ninhydrin and Zinc Chloride if needed. Hope you have some success.

[H. B. James]

My little unit still works in the 20th century. Our method would be to put the thing in the superglue tank and leave it for ten or twenty or thirty fuming sequences. We would leave it in with other evidence being processed one time, but not take it out until we either (a.) develop latent prints, or (b.) give up. That has worked for us on raw wood before. On one occasion, I believe we left a board in there for months before some clear ridge detail had developed. It seems to take the superglue a long time to draw the fingerprint residue that has soaked into the wood back out. If you don't have the budget for fancy cameras or chemicals, throw the sucker into the superglue cabinet and forget about it for a while. That will work where nothing else will.

[Graham F]

You state that the wood is dark - if it is not overly dark, then silver nitrate - speed up process with a lamp/light , then photograph. Had great results with pick axe handles and broom handles, etc.

Smooth wood can be considered for PD, then photography.

[kimba325]

Thanks for all of the great information. We are currently waiting for delivery of the UV/IR Fuji so maybe we will delay and try that out. If not we will try some of the chemical methods mentioned.