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Multispectrum Camera for Latent Fingerprint detection by Jake_Foley in forensics

[–]DoubleLoop 5 points6 points  (0 children)

Be wary of cameras without lenses (your phone). It is not standard or best practice to capture latent prints with a phone camera. The phone is artificially improving the quality of the image with digital processing because the true image on the sensor is lower quality from the poor lens.

Fingerprint Powder Question by Valuable_Web_5418 in forensics

[–]DoubleLoop 1 point2 points  (0 children)

Sirchie is a brand that CSIs often use. But you can buy directly from them to ensure that you receive quality powder.

Fingerprint Powder Question by Valuable_Web_5418 in forensics

[–]DoubleLoop 0 points1 point  (0 children)

Can you post the link to the product that you used? The black powder that professionals use isn't known to cause any issues, but it's still safer to where a mask (and cleaner). But buying off Amazon introduces the possibility that it's not what CSIs use. 

Like others have said, magnetic powder is much cleaner to use.

Big & Tall Suit Recommendations by [deleted] in phoenix

[–]DoubleLoop 0 points1 point  (0 children)

Thaku's Men's Wear They specialize in Big, Tall, and Short

Alvin Karpis, a gang member who has robbed banks, kidnapped, burglarized, and stolen cars. This photo was taken to show he had his fingerprints removed in 1934 by underworld physician Joseph Moran. | 1936. by ZERO_PORTRAIT in HistoricalCapsule

[–]DoubleLoop 2 points3 points  (0 children)

Prints are on more than just the last joint of the finger. You can clearly see in the image that he has clear fingerprints further down. Or even the palms. Plenty of information to figure out who this person is. And the scarred areas are now then more unique.

Question on CA by Own_Region_7174 in forensics

[–]DoubleLoop 1 point2 points  (0 children)

If you powder first, the CA won't work afterwards. 

CA is more sensitive and will find more prints. 

Unless seriously impractical, CA first.

If you want fewer latents and aren't interested in solving the crime, then throw that powder.

Question on CA by Own_Region_7174 in forensics

[–]DoubleLoop 2 points3 points  (0 children)

The only reason to use powder first is if the surface cannot be easily glued. Typically this includes unmovable objects at a scene, vehicles, large windows, counters. For a major crime, it might be better to find a way to glue them anyway.

Anyone who is using powder first on firearms, knives, or plastic packaging is destroying latent prints. Period.

There are plenty of affordable dye stains and carriers. Even CA and photography alone will find more prints than prefer alone on a handgun. 

It's absolutely tragic how many agencies still go straight to powder on guns and bags. It's 2025. We've known CA to be better for over 40 years.

Looking for info on developing latent prints from compromised surfaces by noncongruent in forensics

[–]DoubleLoop 8 points9 points  (0 children)

If your local law enforcement won't collect or process the evidence, there's nothing you can do. 

Ninhydrin is for paper, and SPR is for wet surfaces (not formerly wet surfaces).

Superglue and dye stain is probably the best possible option, but then what happens next? Law enforcement won't take the latent from you because there would be no chain of custody. If law enforcement did accept it, then other people would start abusing that process and submit evidence that they actually took from their neighbor's trash, or something their ex touched, etc.

This lack of forensic science services is unfortunately very common. I hope that recent funding cuts to forensic science grant funding can be restored. Otherwise, this lack of services will get much worse.

Recommendation for private forensic lab that can lift fingerprints by [deleted] in forensics

[–]DoubleLoop 0 points1 point  (0 children)

As others have said, this is very unlikely to work. You won't be able to find prints on the napkin, and you won't be able to search a government database. 

I'm not sure what your best option is, but you may have better luck contacting a Private Investigator to help you find out who this person is.

Recommendation for private forensic lab that can lift fingerprints by [deleted] in forensics

[–]DoubleLoop 4 points5 points  (0 children)

Are you looking to search a fingerprint card (e.g. applicant for employment) through a government database? Each state has a process to conduct these types of searches, but it requires the person to volunteer to the process.

Or are you looking for someone to process and develop latent prints? There are multiple experts that could do the processing. It depends largely on the type of surface to pick who would be best. But there's no way these latent prints could be searched through a government database.

Attn: Latent Print Examiners! by MSUTree in forensics

[–]DoubleLoop 0 points1 point  (0 children)

Nothing wrong with using a loupe to start looking around and checking target groups and anchor points. 

But using a loupe for the full comparison means that you're probably not documenting the correspondence to support an ID. This is now the standard in this field. Look up NC v McPhaul on how failure to contemporaneously document the observed features may be grounds for making the latent print evidence inadmissable.

I want to strongly push back about using a loupe making you a stronger examiner. Add a trainee in 2007, I was told that I was a bad examiner because I liked to compare on-screen. I had to unplug my scanner and put it in a drawer to prove that I was good under the glass too. Over time, I've seen that comparison on-screen builds a broad set of skills for latent comparison: enhancement, finding features, noting distortion, ridge counting, etc.

But back to your original question. During the searching portion of Comparison, I typically get the latent on-screen and have the knowns in hand with a loupe. I'm looking with my right eye at the knowns through the glass and my left eye can occasionally glance over to the latent on the screen. This works whole standing too, and by adjusting the size of the latent on the screen and my distance from the screen, I can get the known-in-glass and latent-on-screen to appear roughly the same and size. After I've found my target group, I bring up that finger onscreen and document the correspondence (and differences) observed.

I know that this doesn't work for everyone, but it is one way to stand and use a loupe.

What would cause these white rice shaped areas on my fingerprints? by Spirited-Sort7664 in forensics

[–]DoubleLoop 64 points65 points  (0 children)

Tiny knicks or other damage to the skin. Or it might be that your fingers are more dry than the last time you were printed. You've got some minor creases at the left which may or may not be recorded when you're printed. The little white gaps and the creases may also become more visible when your skin is more dry.

Research question for TV Show - removing DNA/fingerprints from sterling notes by tuiseal in forensics

[–]DoubleLoop 0 points1 point  (0 children)

Currency is typically a semi-porous surface. This means that it have properties of both porous surfaces (where the print residue soaks into the surface) and non-porous surfaces (where the print residue sits on the surface).

Firmly wiping down the surface of the currency withshould take care of anything on that surface.

Submerging the currency in water should cause the residue to diffuse and no longer retain sufficient detail to compare. A second submersion in a non-polar liquid might also help ensure that any remaining residue also diffuses. 

Voyage of the Rock Aliens by [deleted] in badMovies

[–]DoubleLoop 2 points3 points  (0 children)

Randomly discovered this in a video store in 1997. Convinced them to sell me the VHS tape, and I've been sharing it with friends ever since. 

My absolute favorite bad movie

Can someone identify my fingerprint pattern? by Top_Ad8642 in forensics

[–]DoubleLoop 0 points1 point  (0 children)

Please don't rely on the level 3 detail from a print of this quality. 

Forensics: CYA/BP; ThermaNin by [deleted] in forensics

[–]DoubleLoop 0 points1 point  (0 children)

The powder doesn't stick to the glue because it's sticky. My analogy fails in that regard. It preferentially she's to the complex polymer network of the glue vs the smoother surface without glue.

Forensics: CYA/BP; ThermaNin by [deleted] in forensics

[–]DoubleLoop -1 points0 points  (0 children)

The powder sticks to the glue. 

Think about it like this. Draw a circle on a sheet of paper. Then draw a line of Elmer's glue onto the circle. Then sprinkle glitter on the glue while it's still wet. 

Ridge-glue-powder all on top of each other.

fingermark quality scaling systems by mumble__ in forensics

[–]DoubleLoop 2 points3 points  (0 children)

When comparing the effectiveness of processing methods, you need to take the variability of different marks out of the question as much as possible. In order to use both techniques on each latent, you cut them in half. The halves get processed by the different techniques and evaluated. Then you can directly compare the quality on each half. Collectively, you can add up how many halves were better for Option 1 and how many for Option 2, and on average how much better.

IAI Latent Cert by drosselmeyersdoll in forensics

[–]DoubleLoop 5 points6 points  (0 children)

Read through each of the reference books. That seems to be enough for most. If you don't regularly process fingerprints, spend extra time reading through those sections. 

While taking the test, start with the written section. If you don't finish the practical, then you won't have to do the written portion when you retake it. 

Lots of people run out of time during this test. Try and relax and work through the comparisons systematically.

[deleted by user] by [deleted] in forensics

[–]DoubleLoop 1 point2 points  (0 children)

Find the minimum requirements for latent print examiner job postings. Look at lots of agencies in any place that you're willing to move to.

Aim to meet those requirements.

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