Photographic Film as Evidence

<p>Does anyone know of any device which can be used as a tool to detect if the photographic film has been tampered?</p>

Before exposure or after exposure or both?

<p>No way if the actual film is not provided. A contact of the neg can be printed in one corner, But if it was altered with dye it still is no proof.</p>

<p>Nikon and Canon sell image authentication programs to detect changes for digital files. Canon`s goes under a different name.</p>

<p>Considering that a very high resolution scan can be made of the original film, expert retouching done, and then a new film written back to camera stock using a high end film recorder, it would be extremely difficult for even an expert to pick up on the fact that the image was not original. Having more than one exposure on the roll is important.</p>

Do the microscopic scratches on the film match the camera? A film recorder's camera will most likely have different longitudinal streaks than the presumed camera.

 

An imprinted date should not be considered as reliable since a databack can always be re-set.

<p>Are you asking the question in a legal sense, or just generally speaking?</p>

<p>My brother used to be a cop in Orlando, Florida. He has also long been an amatuer photographer, starting with a Nikon F that he bought new. I'm pretty sure that he has told me that it was mostly a matter of maintaining the chain of evidence, from one identifiable, trusted person to the next.</p>

<p>When photographs were used at trial, the original negatives were always available for examination, in the event that someone questioned the authenticity of the prints.</p>

<p>We had an email converation recently about how this is handled in today's digital environment. He has not been a cop since before the digital revolution, so he doesn't really know how the situation has changed.</p>

<p>Paul Noble</p>

<p>It still works the same way with digital. It's all about documenting the chain of evidence and a police officer or technician verifying under oath that the photo submitted in evidence accurately reflects what the actual crime scene showed [or accident scene, etc]- and that the negatives [digital media] were kept secure with access strictly controlled and documented and that no one has altered them from their original state.<br>

I handled my department's photography, processing and evidence storage and I can say that I was only asked under oath by defense attorneys if the photos were accurate and unretouched. Not one attorney ever asked to see any negatives in any case that I handled or was familiar with.</p>

<p>Before and After the exposure of the film if there is a need to prove in the court of law that the film has been tampered. How to establish if it has been tampered or not?</p>

<p>Judging from the responses, it would appear that a photo in this day and age is very weak evidence whether there's a negative or not. The more there is of the original roll of film and the camera that took it the better, but even that can be easily faked if had to be and the stakes were high enough. Other corroborating evidence and the sworn testimony regarding the chain of evidence are ultimately all the court would have to go on and if the integrity of those presenting the evidence is questionable, you have almost nothing. Anything can be faked now and a photo on its own means little except to support other testimony.</p>

<p>Chandan,<br />Please read my answer above. Proof of continuity of the chain of evidence supplied by the testimony of reliable witnesses ( the police ) is all that's needed. IOW- someone swearing in court that the image has not been altered. Period. Just like the admissability of any other type of evidence- a written report or an eyewitness or line-up testimony. If the defense can't show proof there's any doubt about the photo, then it's judged reliable.</p>

<p>John,<br />A photo in the pre-digital age could also be faked. It all boils down to a credible witness's testimony and proof of proper evidence storage. That's all, nothing more. Like I said, In 30 years I've never had a defense attorney ask to see the negatives.</p>

I don't think Chandan is asking about photos that were taken by a police photographer. A person accuses another of assaulting him and offers photos that he took himself as proof. The color negative could be spot toned with greens and reds to make bruises on the face. I hope you are not saying that all the retoucher has to do is swear in court that the image has not been altered and he is home free.

<p>The SCENE and EVIDENCE can be faked if film or digital.<br>

<br /> Here I print court case posters and do retouching too.<br>

<br /> One can throw a garbage can lid into the air of use a UFO dodgeing wand and create a typical 1960's X-files UFO image; the film has not been tampered. One just has an altered scene with the the garbage can lid; or altered print with a dodge tool that looks like a ufo.<br>

<br /> One could place a gun in a dead persons hand for a crime scene image before the film was shot. That is why " Proof of continuity of the chain of evidence" as mentioned is called into place if an image is questioned.<br>

<br /> At one time some places used alot of Polaroid images.<br>

Images are altered ON PURPOSE for court case posters too; ie cropping; ie adjusting colors and white balance on a 30 year old faded original. I just keep track of what was done; so when called into court there is a valid reason of why; and maybe an unaltered version is shown too. The purpose of the images matters too. If one lighted up a scene and the case was about poor lighting; well you are in the wrong ie fraud. If it is about the layout of items; ie cropping out and showing only the junk car of many in a junk yard is more OK.<br>

<br /> In sticky cases one shows both unaltered and corrected/croped images; thus the judge and jury and lawyers can see both; ie one is not hiding anything. The first digital images we got for court case images goes back to about 1995; thus digital as evidence is actually quite old; ie ancient history.<br /> There was also a heck of alot of dumb Polaroid /instant prints used; and tonnes of disposible c41/35mm stuff used too; plue a heck of alot of evidence where on has NOT a great image to work with. Ie think faded prints; copies of copies of prints made from crappy scans of prints.</p>

<p>About only 1 out of 100 inputs we get is an actual film original; ie the original was film; it is prints or copuies of prints. You get a many many down the road poor crappy many generations old copy of a print to fool with. The film original and first print are locked away; thus one would be an idiot to alter/retouch a ufo or gun; or gun in a alien/spaceman's hand!:)</p>

I s anyone reading Chandan's question? He is not asking about police procedures, faking of scenes or the use of photos in court.

 

"... if there is a need to prove in the court of law that the film has been tampered. How to establish if it has been tampered or not?"

 

How could you tell if a film has been tampered?

<p>"Does anyone know of any device which can be used as a tool to detect if the photographic film has been tampered?"</p>

<p>No.</p>

<p>I have heard there are such devices for magnetic tape; these machines would tell if the recording made on the tape was the first one, or beyond the first one. Those have been around for some time. Since the late 80s, at least; they were originally used by engineers who dealt daily with VCR tapes and magnetic audio recordings.</p>

<p>The limitation of using this machine's measurements was that it could only conclusively prove one of two ideas: either the recording was the first recording ever made on that tape, or not. Solving the logic problem of "Was this recording tampered with" was more involved than that. Thus, the need for attorneys and not just engineering experts when someone bickered over a tape in court trials.</p>

<p>Keep in mind, "tampering" is not just going to involve mechanical procedure, but also intent. To make matters worse, there are so many ways a piece of photographic film can be used, that one man's "editing" could be another man's "tampering" could be yet another person's "normal use."</p>

<p>For a photographic film, physical inspection would probably be the primary indicator of editing. Retouching requires some skill; not just anyone with the materials will succeed on the first try. By comparison, anyone could easily make a second recording over the top of a first recording on a VCR tape.</p>

<p>With film, the structure will be the structure. Maybe, through some destructive analysis a physical chemist could run some kind of expensive test to determine what part was what. For a nondestructive, descriptive test by machine? I don't know of one. I think physical inspection by an expert would probably be as close as you could reasonably get.</p>

<p>James; one almost NEVER gets a piece of film to make a court case exhibit from; one gets many generations down the road; the film is already locked up.<br>

<br /> With an old Adams retouching machine one can doctor negatives; ie retouch them; but that was from a different era; plus all the marking and pencil marks show up from glancing/grazing angle.</p>

<p>The question doesnt even mention film size either; here I have film in 42" wide roll here for our process camera. One purposely masks off pinholes; uses red pens on defects; makes /made legal maps with contact prints.<br>

<br /> If it is an older photographic film for a legal survey plat; shot with a process camera; it might not be "legal" until all the high mucky mucks hand sign the original we made' from a CAD or hand drawn image. The mucky mucks might use an xacto knfe and change their title; or a goober at the court might add indexing info; or those signed names might fade.<br>

<br /> With a double exposure where a still camera is moved; lighting differences often emerge.<br>

<br /> One can just retouch an image; add ufo's; reshoot the print and the film will have all theses goodies in place. <br /> IF the actual original has been tampered physicallyl one can hunt for the defects; additions; shading with a microscope<br>

<br /> What is the original film tampering; Farmers reducer? adding image intensifer? Adding pencil shading?</p>

<p>With Katrina soaked films the emulsion sides off; one often finds combos of several films on on frame; holes; missing info.<br>

In films that see mold ; one has tampering too; easy to see! :)</p>

I wish that Chandan would clarify a bit. I imagine the scenario is something like:<P>

 

A person is being sued in court.<BR>

The claimant says he has photos and negatives proving his allegations.<BR>

The defendant believes the negatives were altered or tampered with.<BR>

How could he prove that?

<p>The main reason that the State Department requires passport photos to be taken with stereo cameras is that they can compare the image on your pasport with the one they have on file. They can put the two images side by side to create a three-dimensional stereo image which cannot be forged. A single lens camera taking two separate images is also acceptable to the State Department because the two images can be overlayed to see that they are legitimate. The best way to legitimize a photo is to shoot the scene originally in stereo 3d. Any changes in one photo will stand out when the two pictures are put side by side and viewed as a stereo pair. This same principle was first used in WW II aerial photography. You couldn't see that camoflauged Panzer tank from the air with a single lens camera. When the scene was photographed in stereo, a camera at the end of each wing, that tank could be clearly seen hiding in the bushes. </p>

<p>The State Dept does not require passport images from stereo cameras. I just submitted my passport renewal with two prints from the same image file. </p>

<p>In answer to the original question, there is no automatic way to discern faked images, but an expert can usually tell. Look for part of the image where the light is coming from a different angle. Look for abrupt transitions. Look for areas that have a different character (different sharpness or different grain pattern or different pixel patterns). I have friends who forward all sorts of emails to me. Many of them have faked images. I can often find evidence of editing, and I'm not an expert.</p>

<p>Only poorly done fakes can be spotted. The best ones can be made well enough to fool any expert and it's done every day. That's why, as others have said, other corroborating evidence and the testimony of reliable witnesses are far more important than the photographic evidence itself.</p>

<p>This was always true, but more so today. My dad was a great photo retoucher and illustrator who worked on some of the best advertising to come out of Madison Avenue and I used to marvel at the way he created photographs with an airbrush beginning with absolutely nothing but a sketch, and that was primitive compared to what we do today.</p>

<p>I have heard of software that can spot a bad fake however. Of course the developer claims it's infallible, but I've heard that before. Even money can be scanned and faked if you put your creative talent to the task but it's not worth it for the face value of the currency. Evidence could be worth a lot more.</p>

The OP is asking specifically about photographic film tampering. I can't think of anything that could not be spotted just by inspection. A bit of Spotone on the negative emulsion may not be noticed unless it was used on a large area. Double exposures and pie-plates-thrown-in-the-air UFOs AIR I wouldn't consider film tampering. Just something that is done on the actual film.

<p>This was included in my original paragraph: A single lens camera taking two separate images is also acceptable to the State Department because the two images can be overlayed to see that they are legitimate. You need to stop nit-picking!</p>

<p>Steven,<br>

Sorry for reacting to an incomplete part of your post. I agree that stereo views are much harder to fake. Difficult, but not impossible. I recall an Imax film (T-Rex, Back to the Cretacious) that had very good 3D effects created with computer animation. </p>

<p>Back to the original question: I get the impression the poster is connected to the defendant in a suit where there is a need to attack photographic evidence. If this is more than small claims court, I'd hire image analysis experts. Even if the images are so good that they can't determine for sure that the evidence is forged, they can describe how such evidence could have been forged this raising doubts.</p>

<p>Ron that is a great help. If the Image Analyst can describe the methods tools and techniques to commit such forgery isn there a possibility to collabrate the intent and methods of forgery to establish the benefits for conducting such activity. Hence establishing the case.</p>

<p>Pls check this patent which is designed to supplement the claims handling process of Insurance.<br>

<a href="http://www.ipo.gov.uk/patent/p-journal/p-pdj/2006-6128.pdf">http://www.ipo.gov.uk/patent/p-journal/p-pdj/2006-6128.pdf</a></p>