CLPEX Chat Board

Has anyone had any luck processing dollar bills for latent prints? Ninhydrin obviously turns the bills a purple color and I've experienced some ridge detail; however, none that are identifiable. Maybe there is a different ninhydrin mixture I could use since money is made up of fiberous material? We have over $1000 dollars in bills that need to be processed and I am currently looking for other options. Thank you!

Yup... money is tough. The trouble is, if it's been circulated, it's been touched by everyone and their brother. It's filthy, as latent print deposits go, which is why it lights up in practically solid purple when you ninhydrin it.

In our lab, we've had slightly better luck with DFO (no background interference) before the ninhydrin, and Physical Developer (the 'recommended' procedure, according to our training materials) after, which seems to only develop a few prints, rather than bathing the bill in reaction product, like ninhydrin does.

That said, neither my colleague nor I has ever developed a useable print off of money in the time we've been doing casework. We've gotten better ridge detail than with ninhydrin... but not much. Could be we're just unlucky. Or could be... money is tough.

Money is very difficult. My experience has been that Physical Developer works the best. It gives you crisper, more defined ridge detail. Ninhydrin and DFO cause too much background problems because of how much money is handled. The good thing is that DFO/ninhydrin processing doesn't really affect Physical Developer, so you can do them all. But when you do the PD, you're done. One variable to keep in mind about your specific case is how fresh are the bills. If they are clean new bills you might get lucky.

US paper currency is not entirely paper either. This is from the US Treasury's website:

The paper that the Bureau of Engraving and Printing (BEP) uses to produce our currency is "distinctive." A paper manufacturer produces it according to BEP specifications. It is composed of 75 percent cotton and 25 percent linen. The paper also contains red and blue fibers of various lengths that are evenly distributed throughout the paper.

This can be found at http://www.treasury.gov/education/faq/c ... n.shtml#q2

When I was in the document section I had very little luck getting identifiable prints off of money. We routinely tested it with DFO, Nin and PD. I'd say I got useable prints about ten per cent of the time, if that.

One of the other problems, of course, is the evidentiary value of the latent. You don't know the history of those bills (where they've been or for how long they have been in circulation) and you can't tell how long the fingerprint has been there, so.....the accused could have touched that banknote some time in the past.

At best it is one evidentiary cut in a 'death of a thousand cuts'.

I have been successful on two separate occasions using the HFE-7100 formulation of ninhydrin. Both successes resulted in prints that were of a good enough quality for individualization or exclusion. This is over two years, with an average of one case involving money every week. Sure, it gets frustrating, but what a rush when you finally get that print!

Thank you all so much for the feedback. Since we have so many bills I may try all suggested processes to see what I come up with. I also have contemplated about the circulation of the money and the suspect's prints being on it from past exchanges (which is what would most likely be brought up in court); however, my only hope is that I find his prints on several of the bills at once. Hey, no laughing.

Early in my career, I had a case with 14,500 one dollar bills to process, which I did, one by one, using ninhydrin and a steam iron, in accordance with agency protocol at the time (about 30 years ago). We had no lab facilities at the time, and had to crawl out a second story window onto a rooftop to spray on the ninhydrin, since there was no inside ventilation available. I recall having to chase down about 3 bills that blew off the rooftop in the wind. Things have improved a little for most of us since those days of long ago. If memory serves correct, although most of the bills were new, I only developed about half a dozen identifiable latent prints, but did identify a suspect.

In the ensuing years, I have had some success with all three of the previously mentioned processes: DFO, Ninhydrin, and Physical Developer, although by far the most success was with Ninhydrin. The key is not to use heat , and especially not use a steam iron. Instead, allow the bills to dry and sit in a normal interior room's ambient temperature (approximately 68-78 deg F), for a period of several hours to about a week, inspecting for latent prints at least twice a day. My experience has been that if prints are going to develop, the majority will do so in one to three days.

Although the percentage of identifiable prints is still relatively low, this process has yielded the best results for me. It is also amenable to batch processing when dealing with a large number of bills; a loose roll of bills may be placed in a suitably sized glass beaker, the ninhydrin solution poured over the bills to completely cover them, left long enough to completely saturate the bills, and the excess then poured out of the beaker. The bills may then be left in the beaker to dry, and later removed when ready for individual inspection. Some care must be exercised to avoid multiple bills sticking together.
RLT

The suggestion to avoid the application of heat does yield prints with less background. I have also had better luck by diluting my normal working solution of ninhydrin 50% and then allowing the evidence to air dry. This will result in a 8-12 day development time which is an advantage with a large numbers of bills. I have identified many finger and palm prints using the dilute solution.

Dan,

What are you diluting your Ninhydrin solution with for the 50% solution?

And what is your carrier for your solution, ether?

Thanks,
JJ

JJ,
Since Dan has not answered yet, I'll offer a couple of obvious solutions (no pun intended) to arrive at a 50% (of normal) ninhydrin working solution:

When mixing a new batch of ninhydrin solution, reduce the amount of ninhydrin by one half, and keep the amount of carrier constant (i.e., if you normally use 28 gms per gallon of carrier, use 14 gms instead, retaining the gallon of carrier).

or

If you already have some normal working solution available, double the volume of carrier (i.e., one liter of normal ninhydrin working solution, add one liter of carrier).
Regards, RLT

Yes. Tough to process. I have had success using 1,2-INDANEDIONE followed by/ or just Physical Developer.

I use Indandione followed by PD with some success. I've definately had better luck with the newer PD formula that came out of the Secret Service and was described in the JFI a few years ago.

Our money is now made from plastic but a number of years ago our 'paper' money was also made of material composing of cotton and linen; as new money it was also impregnated with some kind of fat which reacted fabulously with the nin, but after a short time the notes shed the fat. We used a 50% solution also, that is we added twice as much carrier than normal.

Likewise success ran at about 1% of total money processed.

Plastic money is much more successful.

`Has anyone had any luck processing dollar bills for latent prints?`.


I hope I`m not stating the obvious to you but less ninhydrin eg a spray gun instead of a dip might help. You might also want to try a very quick dip and leave to dry thouroughly. Take a look at the notes before you apply any heat..sometimes the prints are there before any heat treatment. My own experience has been to leave the notes to dry after ninhydrin and place in sealed bags and leave(secure!!!) for a day or so. I have to say that my own experience is with UK currency and not US. I apologise if I seem to be stating the obvious but I hope this is perhaps something you might not have tried.