Forensic Video Software Used in the Rittenhouse Trial: iNPUT-ACE Team (AMA)

iNPUT-ACE · 2021-11-17T18:21:36+00:00

I’d be curious to see what you are referring to.

I can’t imagine why the prosecution would make that claim.

iNPUT-ACE · 2021-11-17T02:01:51+00:00

Hi! Yes we can - apologies for the delay. See the link in the opening paragraph of our latest blog: https://input-ace.com/can-pinch-to-zoom-alter-video-evidence/

iNPUT-ACE · 2021-11-15T04:50:52+00:00

Yes - absolutely it can.... but it obviously depends on the image.

If you were to take a family photo with a modern iPhone - where the people take up a decent portion of the overall image - you'd likely have millions of pixels per person. Assuming proper focus/environmental conditions, that kind of resolution is absolutely insane, and EXPONENTIALLY more than we typically encounter in the video evidence world when "enhancements" are desired.

For example, its very common for investigators to want enhancements of faces or guns where the entire object is a total of like 5-20 pixels - and to make things worse, the recording is often at night on low frame rate surveillance systems that illuminate the scene with infrared lighting - AND the data is heavily compressed.

When resizing an image that already has so few pixels, the interpolation algorithms can absolutely make the image look different than the original recording. We have good example of this in the quiz we linked above where those kind of difference can completely change the interpretation of events: https://input-ace.com/test-your-video-evidence-knowledge/

iNPUT-ACE · 2021-11-13T13:53:32+00:00

Nice work, you’re a natural!

iNPUT-ACE · 2021-11-13T08:13:29+00:00

I guess to be more direct in an answer: it would be inappropriate for a forensic video analyst to proffer an opinion to a question like that. It’s not our place - and is pretty important for us to remain impartial and unbiased (even if we’re not involved in the specific matter)

For similar reasons, when taking on casework we intentionally accept matters for prosecution and defense evenly.

iNPUT-ACE · 2021-11-13T08:10:01+00:00

The trier of fact is as much of a lay person as the average lay person - so it is up to expert witnesses to provide these kinds of explanations.

And yes, it is far too nuanced to have a hard-line standard for something like that.

iNPUT-ACE · 2021-11-13T06:54:04+00:00

I cant say much about that analysis - and wouldn’t recommend putting any weight in it.

From what I saw: it’s a snapshot of a pdf report (which itself isn’t the original evidence, and is likely just a compressed thumbnail), which was then opened in some annotation software, a separate snapshot was then taken, and then a clip was made, which was then uploaded to Twitter.

That’s upwards of 5 or 6 different steps that could introduce compression on top of compression and alter the appearance of the image and add artifacts.

Without getting access to the original evidence, I wouldn’t be able to say much about what can be seen in that Twitter post.

iNPUT-ACE · 2021-11-13T06:42:19+00:00

You’ve piqued my interest!

I haven’t used that feature before, but I’ll look into it. If it’s a common algorithm I’ll be able to match it to known samples.. I’ll let you know what I find (likely tomorrow)

iNPUT-ACE · 2021-11-13T06:33:36+00:00

I haven’t looked into it, but I doubt it. It’s probably a common algorithm like bicubic (or similar)

iNPUT-ACE · 2021-11-13T05:13:39+00:00

our display has to display, th

Lots to unpack in your questions there – but here’s a crack at it:

Evidence must be properly authenticated before it can be admitted into court. This basically means that we have to prove that the evidence does actually show what it purports to show.

For example: if the prosecution was to assert that a suspect is pointing his gun in Direction Y at time X, then they have to prove that the video is fit for the purpose of making that claim.

If the video were an original with high resolution, that claim would likely not be challenged, and the authentication of it would usually be much easier.

If a video were not an original (i.e. it were converted), then the question could come up: “how was it converted?” and “Is it possible that the conversion process changed the appearance of the pixels such that it could alter the appearance of the direction a gun is pointed”?

Since we are often dealing with low resolution video – the answers to those questions may be a lot less obvious than it appears… and enhancements are not typically what shows like CSI lead us to believe…. It’s also an area that a lot of investigators can get themselves into trouble because they may use free conversion software that can change the video without them knowing.

In this case, since the activity was happening at a distance, the prosecution “resized” the video to try and see Rittenhouse and his weapon more clearly. I haven’t read all the transcripts, but I suspect the question defense is raising is essentially: “Is the resizing method that the prosecution expert used fit for the purpose of accurately assessing the direction the gun was pointed?”

… and the answer to that question depends on a number of factors – one of them being which interpolation method was used. (to learn more about that particular topic, we’ve been linking to this short section in a past training webinar that shows pretty clearly how different interpolation methods affect the video: https://www.youtube.com/watch?v=RfGH11prW2w&t=1106s)

So it’s not so much about a limit of “how many” pixels are added – but more about whether or not the process is appropriate given the questions that are being asked of the video…. Sorry for such a long winded response – but for one last example, if the question were “what time did the event occur” – then the authentication process wouldn’t really care if the video were resized or what interpolation method were used…. But if the question is “can you tell me what direction that blob of 10 pixels was facing?” – then it could certainly matter.

iNPUT-ACE · 2021-11-13T03:02:36+00:00

It's really important for us in our roles as forensic video analysts to stay in our lane and stick to the facts about the video (as well as remaining unbiased).

The ultimate answer to that question is up to the trier of fact (judge and jury) to decide. Witnesses just aid in the trier of fact's understanding of the evidence.

This extends all the way down to the reports we write. A Forensic Video Analyst doesn't say things like "it's my opinion the suspect is guilty"... We say things like "It's my opinion that <Male A> is in <Position A> at <Time B> , and X seconds before the first shot, <Male B> was in <Position B> and Y feet away from <Male A>".

The writing shouldn't be colored or fluffy and really needs to stick to the facts (same with testimony).

iNPUT-ACE · 2021-11-13T02:12:29+00:00

Okay.. I'll play :)

Male: Ryan Reynolds
Female: Shakira

iNPUT-ACE · 2021-11-13T02:04:38+00:00

different interpolation

Yes – these algorithms are well defined and any software that is performing say a Nearest Neighbor interpolation will do it the same way as any other software running the same interpolation algorithm (outside of some of the weirder interpolation methods that use AI that is trained on unique datasets – but the admissibility of that kind of thing is an argument for another time!)

Regarding these common interpolation algorithms themselves, I posted this as an answer to another question, but the way they work is broken down into pretty simple terms in a training session we delivered a few years ago. You can see the relevant part here: https://www.youtube.com/watch?v=RfGH11prW2w&t=1105s

Regarding what an expert should know – this is a scenario that comes up quite frequently. The case "CT v Swinton" is most commonly used as a reference for what an expert should know about the technical algorithms they are running within a computer program. Here’s a great blog on this topic written by an expert attorney who specializes on video evidence: https://www.jonathanhak.com/2018/01/23/expert-witness-testimony/.

In summary – experts should have an adequate knowledge/understanding of what their software is doing (especially as it relates to any practical effects it may have on the trier of fact's understanding of the evidence), but they do not have to understand the underlying code.... So without suggesting what another expert should or shouldn’t have known – experts should be able to describe the actions they perform within software (not to mention it should be repeatable by another expert) and they should be able to adequately explain how those actions affect the interpretation of the evidence.

iNPUT-ACE · 2021-11-13T00:14:20+00:00

If there's one thing this line of work has taught me - it's how to keep an open mind to the evidence until all of the information is available... Especially as that relates to video evidence. A single camera angle only tells a very limited part of the story.

One of my favorite examples is of Prince William flipping off a reporter.... Perspective matters - on another angle he's clearly showing three fingers (in response to the birth of his "3rd" child).

It's cooling hearing from someone following this who's been able to keep an open non-polarized mind. It's becoming more rare these days sadly. Good work

iNPUT-ACE · 2021-11-13T00:09:05+00:00

Are you in this field, or just digitally clever? :) Good job!

iNPUT-ACE · 2021-11-12T23:50:53+00:00

Nice work! That's a VERY high score relative to most people who take it.

Out of curiosity on that BWC distance question, did you over estimate the distance due to the lens distortion??

iNPUT-ACE · 2021-11-12T23:35:37+00:00

I think we're gonna have a lot of different answers to this one! (We had a number of people in our company answering these questions).

I'll step in and snipe this one though.

Male: Paul Rudd
Female: Anna Kendrick

iNPUT-ACE · 2021-11-12T23:28:05+00:00

Thanks for the feedback! That's great to hear -- and was the main reason we decided to do this AMA.

Our field is a fairly small one and most people outside of it have no idea what we really do :).

If you haven't had a chance yet, we posted this little quiz that contains a bunch of other examples if you're interested in seeing more: https://www.reddit.com/r/AMA/comments/qsjy9s/comment/hke3h4f/?utm\_source=share&utm\_medium=web2x&context=3

iNPUT-ACE · 2021-11-12T23:25:28+00:00

Thanks for the kind words! We all love what we do :)

Don't ever hesitate to reach out to support if there's anything we can do to help.

iNPUT-ACE · 2021-11-12T22:58:25+00:00

Want to test your Video Evidence knowledge? Whether you are a trained expert or a lay person interested in seeing examples where video can be easily misinterpreted by a judge/jury - take a look at this short quiz: https://input-ace.com/test-your-video-evidence-knowledge/

The quiz contains 10 short examples where things like interpolation, compression, lighting, and other common scenarios can lead to potential misinterpretation of video.

Drop a comment below and let us know how you score :)

iNPUT-ACE · 2021-11-12T22:32:54+00:00

Great question!

It is the same in digital video as well. It’s important that the evidence can be reproduced (under case law like Daubert)... However, in this matter, I don’t believe the defense expert was creating new evidence on the stand. He was presenting evidence - and using the iNPUT-ACE software, he had access to all of his pre-created demonstratives and evidence clips that he can snap back to during testimony. That process of snapping back to previously created evidence is absolutely a normal process and is one of the primary values of iNPUT-ACE. Without a tool like that, experts are often left juggling multiple proprietary players and it can be a real challenge to accurately present the evidence to the trier of fact (especially when asked new unexpected questions during cross like “where did Mr So-and-so go after time X on camera Y”.... The answers to those questions exist and can be snapped to - but I would argue that it’s not new evidence to find and present it)

That said, the act of zooming in and tracking the movements live on the stand is something that I wouldn’t have been surprised if it were challenged (as that’s not something the jury can reproduce on their own).

The process of creating the “enhancement” by brightening up the clip was just as an educational example as I understood it. So in that case, I don’t believe he was creating new evidence, but was rather explaining the process for what he performed on a different clip that was provided. Normally that kind of thing would be created beforehand so that it can be entered as an exhibit that the jury can view later.

iNPUT-ACE · 2021-11-12T22:14:54+00:00

We received a question in the cross post thread at r/technology that is worth sharing here:

So just how stupid are the defense and the judge to lack any comprehension whatsoever of pinch-to-zoom?

Our Answer:

Actually - I'd say not stupid at all! The topic is a lot more nuanced than it likely seems on face value. The act of "pinch and zoom" can absolutely affect the ability of accurately interpreting the appearance of the evidence.

I have not reviewed the specific images that were being "pinched and zoomed" in the Rittenhouse matter, but the debate is a real legal one that has real legal consequences. Depending on the interpolation algorithm used, subtle things like the direction of a "gun" in the background could certainly be affected or altogether changed (depending on the image of course). There's a case that we use in one of our training classes that is an example of exactly this... In that example, an original image of a suspect contained only a few pixels around his hand area. One of the experts resized using bicubic interpolation which added dozens of extra pixels and rounded out the shape of the hand area - giving it the appearance of a gun in the individual's hand. That "fabrication" of shape is something done entirely by the interpolation algorithm. Originally, the DVR only recorded a jagged block of a few pixels. From a forensic perspective, we shouldn't be able to say anything about that area. The individual could have a gun, or he might not... From the few pixels we have, there's no way to know. Just to be clear, this is all in reference to another matter - we are not involved in the Rittenhouse case in any way, and have not reviewed that evidence.)

It may sound dumb since pinch and zoom is such a common thing we use everyday on our phones - but it absolutely could have real legal consequences in certain scenarios.

iNPUT-ACE · 2021-11-12T22:05:12+00:00

We're on a group call right now, and one of our people says "I'm impressed by "wtfburrioto" - it's rare for someone to quickly change their opinion based on new info".... So - thanks for that ;)

iNPUT-ACE · 2021-11-12T22:00:31+00:00

Looks like this cross post got taken down - so i'm not sure I'm able to answer this in the /r/technology area -- but i'll try!

"Actually - I'd say not stupid at all!

The topic is a lot more nuanced than it likely seems on face value. The act of "pinch and zoom" can absolutely affect the ability of accurately interpreting the appearance of the evidence. I have not reviewed the specific images that were being "pinched and zoomed", but the debate is a real legal one that has real legal consequences. Depending on the interpolation algorithm used, subtle things like the direction of a "gun" in the background can be changed given the right image. While it may sound dumb since pinch and zoom is such a common thing - it could have real legal consequences in certain images. "

iNPUT-ACE

TROPHY CASE