After the Webinar: Case Closed! A Case Study of CSI Evidentiary Photography. Q&A with Andrew Reitnauer

Webinar presenter Andrew Reitnauer answered a number of your questions after his presentation, Case Closed! A Case Study of CSI Evidentiary Photography. Here are just a few of his responses.

 

Audience Question:  Are cell phone cameras, such as an iPhone, acceptable for taking crime scene images? 

Andrew Reitnauer: The proper answer to that would be no. The fact that your hand holding and the overall capabilities of the camera within your iPhone may seem like they’re very high-end and they are getting pretty, pretty high quality. But normally you would want to take these using a standard DSLR camera. That being said, there are obviously circumstances where having a photograph taken from your iPhone is better than not having a photo at all. If you have a situation where you have inclement weather, or there may be evidence that could be lost, having some sort of photograph is better than none at all. And it’s obviously something you would document if it’s not captured under, you know, the normal procedures of your agency or within best practice, we want to be transparent. So, being able to just document that the photos were taken from a cell phone due to circumstances A, B, and C would be acceptable. And, you know, the photos may be of sufficient quality. They may not. But it’s better to have something than nothing.

 

Audience Question: Referring back to your fingerprint image polling question, will Level 2 be the pores that could be used for identification?

Andrew Reitnauer: The pores are actually considered level 3. The individual characteristics such as ending ridges, and bifurcations, are your level 2 points, those red dots that I was marking. With level 3 details, those details are not searched in AFIS because they may appear in your prints, but they may not. If you think about something as simple as the weather of the area, when it’s very hot, your hands may be sweaty, the pores are open, so you may have those details present. Versus if it’s very cold outside, your skin shrinks down, and your pores are closed. If they’re present in both the latent and the known we can use those during comparison but they’re kind of like the sprinkles on the Sunday.

 

Audience Question: I have found a 90-degree angle removes the overhead lighting. So how did you manage it?

Andrew Reitnauer: I was photographing these at about 45 degrees. One of the kinds of myths within some of the evidentiary photography guidelines is that all impressions have to be photographed at 90 degrees. And that’s very true, especially with tire marks and shoes where impressions because size really matters. But within latent prints, your skin is flexible. Actually, no two impressions should ever be able to overlay on top of each other and align perfectly. If you see that it’s actually a forgery. So, spatial relationships within the characteristics will change, depending on pressures and things of that nature. So, the 90-degree rule with photographing fingerprint evidence really is not as applicable. Because there is a variant involved.

 

Audience Question: Regarding using cell phones for photography. In animal cases, we generally have a less controlled scene than in the ones that you mentioned, especially if it’s our first response, and we snap photos to be used later in a search warrant to get a more secure scene. Any suggestions on how we might improve our photography given these limitations? 

Andrew Reitnauer: The one thing I would say is, just be mindful of your lighting. Especially, I know I have an iPhone myself, if you’re using that outside and it’s darker, you have kind of a long exposure. So, you may want to consider making sure your flash is turned on, even though it may cause a little bit of brightness and some areas, it may also improve the clarity of the subject you’re actually trying to photograph. So, you can take as many photographs as you need. But it would be, maybe advantageous to, to have the flash on as well, because, once you get to dusk and the sun is starting to set, sometimes the exposure is very long which causes some inherent blur.

 

Audience Question: If we don’t have a tripod handy, could we use other photography trips like leaning against a building or some other stable location?

Andrew Reitnauer: Yeah, see if you do not have a tripod available to you, you can. And as you just described, kind of use your body as a tripod. You can also sit your camera down on something, if you are photographing, say an impression on the wall and you were able to set your camera on a table or a chair that would be stable and you could certainly do that as well. I would just also recommend being transparent that that’s why the circumstances were that you used to capture that photo just in case there were questions that popped up later. You always want to make sure that, you know, any information or any practices that you perform are documented thoroughly from the very beginning. Another thing you can do is change some of your camera settings to try and get that shutter speed quicker than 160th of a second to kind of reduce that blur. So, that might be a situation which you would increase your ISO settings a lot so that you can get that shutter speed to a point where you can start to eliminate some of that blur.

 

Audience Question: Any tips for photographing necropsies? With so much fluid we experienced lots of glare or reflection. We have less sophisticated cameras than you do. 

Andrew Reitnauer: Sure, one of the easiest ways to reduce reflection is just to change your body position, and it doesn’t have to be a lot. Just changing your camera to the subject by 1 or 2 degrees can actually change that linear relationship of the light and may actually eliminate some of the glare that you’re getting back. I’ve had the same situations with photographing post-mortem impressions on, actually photographing fingers. And sometimes I just needed to change the position of the camera a little bit to help reduce some of those, those reflections when they’re not wanted in a photograph.

 

Audience Question: Do you worry about having to explain perspective distortion if you capture a print at an angle? 

Andrew Reitnauer: I do. One thing that, again, is a key with all expert witnesses, is you really need to be able to explain why. And in this situation such as what I was photographing in this case. Again, I didn’t have a very high angle to the table. But I could explain if I was asked why the camera was not at 90 degrees, that it was not visible at 90 degrees, given the position of the light source, I was only able to visualize the impression using that light at a certain angle which meant my camera had to be used at a certain angle and I compensated using my aperture settings, and was able to then visualize and capture the impression appropriately. Ideally, we would want to be at 90 degrees, because you’d have everything in focus, no problems, but sometimes that just doesn’t quite happen. So, we need to be able to kind of adjust based on the knowledge and skills that we possess.

 

Audience Question: Do you use flashes, or can that change the picture? 

Andrew Reitnauer: Flashes can certainly be used. Your flash acts almost like your flashlight or an external light source. So, again, depending on the angles, you’re using it. If you have the remote cord, the hot shoe cord, you can change where your positioning of the light is. I have certainly used my flash in a multitude of circumstances to photograph friction range impressions because it can very much act like your light source. You may just need to really be a little bit cognizant to preview the image and, if you have to make any adjustments, just make those mental notes on, “Okay, I need to change this angle, or my positioning a little bit.” But you certainly can use your flash as well.

 

Audience Question: Does equalization render a high-quality submission ineligible? With a substrate that has a significant tonal imbalance appearing to benefit from it, I worry about it being degraded. 

Andrew Reitnauer: That is very technical. I’m not sure I fully understand the question, to be honest. Maybe kind of in a general Photoshop sense, I will say that within any image that you process in the Photoshop platform, there will be metadata saved, There will be every step along the way saved. And that’s always going to be very important to maintain. Anything you do to an image should be able to be reproduced. So, if you’re starting off with a very high-quality image and anything changes along the way that should be tracked within the metadata of the image. With the overall integrity of the image, using some of the techniques, you may have a little loss of clarity because of the removal of certain color values or tonal values. But usually, it doesn’t have enough of an impact to warrant something to go from of value for comparison and no value or ready for AFIS to I can’t search it in APHIS. Usually, it does still maintain that integrity.

 

Audience Question: In your case study where there are unique challenges, given that your fingerprint evidence was the only thing used to prosecute this case? 

Andrew Reitnauer: Actually, in this case, once presented with the evidence, the suspect confessed. So, it kind of kind of became a little, I don’t want to say easy, but things fell in line a little bit. There wasn’t a huge amount of challenge to the evidence itself. However, the evidence is what prompted the detectives to actually speak to that person. If it wasn’t for that, there may not have been any details that came out to warrant that follow up.

 

Audience Question: With your case study, did you enhance the impression with conventional powder? I think you did, and you said it kind of obliterated the prints? 

Andrew Reitnauer: Yeah, I typically I like to use bi-chromatic powder, especially when you have variants surfaces like that. But I was using bi-chromatic powder and it actually adhered to the entire table. And I neglected to say it before, but one of our theories was that the decedent had used Endust on this table to clean up maybe within a couple of days of the incident. So, there was kind of that greasy leftover surface just a little bit, which adhered to the powder.

 

Audience Question: How do we get the metadata from a photograph? 

Andrew Reitnauer: If you have the photograph open in Photoshop, you would go to, and let’s see if I can remember the drop-downs. File, and then there’s an option for Info, Image Info. And you can actually see not only the metadata that was performed during the processing of the image in Photoshop, but it actually will maintain the camera data so, you can see what model, the serial numbers, the focal length, everything that’s in there. But it’s always important to, if you do use Photoshop at your desk, to make sure you go into the properties, and make sure the metadata is turned on, because sometimes, by default, it will not be turned on. So, you want to make sure that the detailed log is enacted on the settings on it.

 

 

Click Here to Watch a Recording of Case Closed! A Case Study of CSI Evidentiary Photography.

 

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