CTS vs. Digital Imaging

[jonstwedder3]

I have to admit, I am not a big contributor on this site. I enjoy reading the posts from time to time and sharing information but rarely feel the need to give my two cents. After all, who am I? After taking this year’s CTS test I feel I have to publically comment because this test injures our science on two fronts. The science of fingerprints has been under attack for many years now. In my opinion we have done a good job defending our honor. During the same period, we have been making a transition to more and more digital imaging. Admittedly, many examiners have been hesitant about making this transition. I have been a proponent of digital technology and have done my best to defend making the change. However, it has been an uphill battle to make some examiners more comfortable with it. We may not want to make this change but the reality is the public has pushed us in this direction. All efforts by the manufacturers are going toward digital because that is what the public at large wants. Law enforcement photography has always been a minor part of this industry. Many times we have been forced to make changes when technology changes. This isn’t always bad but it is reality. One of the biggest complaints I have heard from examiners is the printed output of images. In the past, I too have felt the frustration. When I first started digital imaging, looking at prints on the monitor was discouraged. Current monitors have improved 1000% since I started. However, for better or worse, printed output remains the preferred method because it fits better in the workflow of most agencies. On the printer side, technology has really improved. There are a couple of printers out there that are really getting close to satisfying all our needs but I don’t want to make a sales pitch. So what is my point? Fingerprints are under attack and at the same time examiners are reluctant to go digital. Each year, I try to understand what the philosophy of the CTS test truly is. Is it to test the ability of latent print examiners to make sure they have the necessary skills to do their job? Is it to see what examiners across the nation are willing to identify? Again, I am not sure. If the philosophy of the test is to make examiners struggle over identifications due to poor quality reproduction then they did an excellent job. If the philosophy is to discourage examiners from considering digital technology because of poor quality reproduction, then once again kudos. Having difficult latent print comparisons on a test with good quality reproduction is a good thing. It is a true test of the ability of the examiner. Having easier prints but making the test more difficult with poor reproduction is wrong and serves no purpose. You cannot test the ability of an examiner by intentionally or unintentionally messing with the quality of the reproduction. This can even have an adverse effect on the science of fingerprints and the acceptance of digital technology in the court if someone makes a wrong call due to the quality of the reproduction. Shame on you CTS. (By the way, for all you latent examiners considering digital, it’s better than this).

[Charles Parker]

Jon, when digital first came out I was not a fan, but in the past 12 years, you are right it has improved 1000%. Using a scanner, desktop with PS CS3 is great. I do not worry about output because all our case files are digital so after I finish my enlargements, etc, I just drag them over to the E-File. We do have a great printer but it has been months since I have used it for any type of physical documentation.

Now on to CTS. I have been taking them since 1999, and have examined some going back to 1995. I have read on ocassions that someone is complaining about the quality but I must admit that I have not see a bad----poor quality reproduction set-----until this year. The latest CTS I completed just last month was by far the worst quality of reproduction that I have seen from them. Now it was just not me either, each LPE I talked to in the office said the same thing. The reproduction quality this year was the worse.

I do not know what happened with CTS but their QC got out of whack.

I am now a fan of digital and sold all my film cameras and I have 3 digital ones at home. As far as scanning and working with them on the desktop, it is for me superior than film. In the past I would have to take the LP and go to the camera, take my shots and send the film out for developing and printing. Get those back in 3 days to a week and then have to file the negatives.

With the e-file, scan it, work it through PS, drag it into the e-file and go on to the next one. I can work with contrast and resolution and not have to send the negative out for a couple more sets. It is great.

[reidsm]

I don't have a lot to add about the digital imaging, but I will get on board with the previous post that this year's latents from CTS were the worst ever. Every examiner in my unit agreed that the quality was substandard to say the least. I contacted Competency Assessment Services Limited from the UK (who is now an ASCLD/LAB proficiency test provider). They sent me samples of their latent proficiency test, and I was very impressed. They are a little more expensive than CTS, but much clearer.

[George Reis]

I'm not familiar with CTS (I don't do fingerprint comparisons anymore), but we began doing on-screen fingerprint comparisons when I was with Newport Beach, CA Police Department in 1992. I began teaching this method in 1995, and continue to do so. I've never understood why anyone needs to, or wants to, make 1:1 prints of fingerprint images. It made no sense to me when using film, and makes no sense to me in a digital workflow. And, our monitors were just fine for this in 1992 - nice, sharp CRT monitors that you could fill with a fingerprint image (or a section of a fingerprint image).

George Reis
Imaging Forensics

[Ann Horsman]

Thanks for bringing this up. I was the unlucky recipient of one of CTS's horrid digital image LP tests two years ago. I left one print as unidentified as it was so poor I could not see enough detail. I made sure at the conclusion of the 'test' that I made my managers aware I was very uncomfortable with the lack of quality to the test. Good thing I did just that. I have felt that the CTS tests have significantly declined in quality for several years now.

I do not think they (CTS) put a very good product out and too wonder the same way as George does. I enjoy my Photoshop enhancements and enlargements immensly.

[briano]

Look at the calendar, it is 2009. I can't believe anyone in this profession would still be using film and examining latent print images at 1X1 with a little magnifier.

[RL Tavernaro]

I've never understood why anyone needs to, or wants to, make 1:1 prints of fingerprint images.

Look at the calendar, it is 2009. I can't believe anyone in this profession would still be using film and examining latent print images at 1X1 with a little magnifier.

George & I have had a discussion or two on this topic, but never had the time to get it resolved.

Briano, if you're too quick throwing out that old bathwater, the baby may still be in it. Have you never been asked to compare two fingerprints in a courtroom, using only two 1:1 images and a 'little' magnifier, with your credibility on the line?

Don't get me wrong, I'm a digital proponent. However, while we strive to maximize digital advantages, we should remain cognizant of inherent limitations, even as the technology evolves.

Why would any examiner still want to use original 1:1 images of both latent & known prints, instead of taking advantage of the digital technology we have available now? How about efficiency & maximizing human resources available. For example, an examiner receives a comparison submission containing 32 latent lift cards, and 12 suspect fingerprint cards. It is typically a simple matter taking a few moments to eliminate a substantial number of the potential 3,840 or more individual comparisons, using just your eyes supplemented by a 4-5X magnifier. How long would it take just to digitally capture (whether by camera or scanner) all the images, before the first comparison is even attempted? Even if your agency has committed to digital imaging & storage (as apparently Charles' has), and the examiner only sees digital images, it is not likely to permit the most efficient initial review.

Of course, when the choice is between digital imaging and conventional film photography, the efficiency ratio changes to benefit the digital approach. Even then, I believe there is an efficiency argument to be made in favor of comparing 1:1 images with our unaided eyes, supplemented with a magnifier (if the prints are of good enough quality). In any event, I offer no argument to the digital approach after the initial search has been narrowed down to one or a few individual fingers, when the prints are more complex, or lacking in clarity/quality.

I am in agreement that the technology has improved greatly, especially in the past 20 years, however I submit there are still limitations. We are beholden to the hardware & software available. Even with the improvement in automated processes, the capture of an individual latent print is still subject to the complexities of that print & it's environment, along with the camera or scanner we are using. I recall reviewing a latent print identification, where a digital image was used for the comparison & identification. The identification was originally questionable, until the original latent print was examined. Although contrast was better in the digial image used for the comparison, significant detail had been lost, turning a routine identification into a difficult one. This is really no different than dealing with an improperly printed film photograph, however if digital storage is used, & the examiner never sees the original, a potential for error is created.

Regards, RLT

[GEilers]

I don't comment too often, but had to throw in my two cents on this topic. Thanks to George Reis for his fantastic book "Photoshop CS3 for Forensics Professionals: A Complete Digital Imaging Course for Investigators" Wiley Publishing 2007, which served as inspiration for our digital image based latent comparison process and referenced in our article in Evidence Technology Magazine, July-August 2008, Volume 6 No 4, pg 30-33. The publication is available for viewing online at the Evidence Technology website.
Lakewood PD Forensic Identification Team Latent Examiners have been utilizing a digital image based comparison process for about a year and have found it to be a great way to conduct latent comparisons and generate documentation for future reference. Rather than go into detail about the process, it is explained in the article.
I have been taking CTS tests since 1989 and have never been a fan of the quality of the tests, or should I say lack of overall quality. Perhaps someday another company can produce a test that can truly judge proficiency, if that can really be defined by a single test. We have incorporated the digital version of the test into our workflow process, therefore eliminating the need to print images, and can utilize Adobe PhotoShop to process the images to more effectively make comparisons.
Since the latent print comparison process is moving more towards digital imaging and not relying on the traditional magnifying loupe, I would like the IAI to move towards what I proposed at the 2004 IAI Conference in St Louis, that they develop a digital image based certification test and proficiency testing process. A primary hurdle would be to prevent any images from being saved to a storage device and unethically used later.
Overall I would encourage latent examiners to embrace the digital image process for latent comparisons, you will love it once you have experienced it on a daily basis. I would also like to see an alternative to CTS for testing and establishing proficiency.
As a side note, Hi to Bob Tavernaro, and thanks for providing training at Arizona Identification Council (AZ regional IAI) conferences years ago when I was just a novice at latent comparison and now a CLPE since 1988.

Greg Eilers, CLPE
Criminalistics Supervisor
Lakewood Police Dept - Colorado

[RL Tavernaro]

Hi Greg, & thanks for the greeting. I hope that I was able to provide something of use. That was quite a few years ago. And congratulations on being Criminalistics Supervisor in Lakewood. If I knew that, I had forgotten. Are there still people there who break out laughing at the mention of a certain individual from Lakewood PD who was hired at one of my old agencies (many years ago & not in a forensics related position)?
Regards, RLT

[Amy Hart]

Thanks, John O., for raising this issue. I was very irritated by the CTS test. I thought a proficiency test was supposed to mimic actual casework. Instead, I had to look at images that appeared to have been deliberately blurred to make the test challenging. If I found such an image in actual casework, I would go back and photograph it again. It would violate my laboratory's standards to have latents that looked like the ones on the test - they are clearly (ha!) not an actual representation of the original. Looking at this kind of test does not make me a better examiner. It makes me a more irritated examiner, and I am irritable enough already.

My critique of the test can be summed up as follows: The creators were too lazy to generate latents that were actually somewhat difficult to find.

[bayareacriminalist]

I agree, the images in the 09 CTS test were so blurry! I had a headache after doing this test. I called CTS and told them the images seemed unusually blurry (I have taken several CTS tests over the years). I asked CTS if the blurriness was part of the test and they said no. They were very concerned and apologized for the inconvenience.

[Darrell Klasey]

So some poor examiner makes a wrong call (false negative) on a blurry print and his/her department hangs him/her out to dry. But CTS is sorry for the inconvenience. I haven't seen the test, but have taken CTS tests in the past with a former employer. Doesn't anybody at CTS QC these things?

Darrell Klasey

[Charles Parker]

RL---I need to clear something up. When I was talking about digital imaging I was referring to those that are border line or has a question of sufficiency. I was not referring to all latent prints.

About 96% of what we get are lifted prints from the field. The remainder are digital images either taken in the field or in the Latent Lab.

You are right in that the vast and I repeat the vast majority we do the old fashion way with a magnifier and eyeball.

But you remember the old days where if you had one that was border line or extremely light you would photograph it and send the film out to be developed and printed. Digital has taken that pain away.

I can say that since it is easier that I do more and scan more for a better look than I did say 20-30 years ago.

Digital has made things easier, but the majority of what I do is still old-fashion magnifier with pointers.

Sorry for the confusion.

[RL Tavernaro]

Hi Charles,
Ah yes, in the good(?) old days! Sending out to the photo lab often meant me walking over to the darkroom & doing the work myself. We used polaroid to great advantage (anybody want to buy a used MP-4 copy camera?), speeding up the process for the very reasons you stated. I am in full agreement with the advantages of digital imaging on the more difficult/complex latents, not only on turn-a-round time, but with the availability of additional tools such as FFT, that I certainly could not duplicate in the darkroom.
Regards, Bob T. (also know as RLT)

[George Reis]

anybody want to buy a used MP-4 copy camera?)

I don't know if you're serious Bob - but I would love one. If anyone has one for sale, please let me know!

As to workflow (for those discussing it) and what's easiest - for me it was frequently a combination of analog / digital. But, that's aside from the original points of this thread. I did look it up, and apparently CTS offers a version of the latent test on CD - it's test number 518.

George