Wednesday, 26 September 2012

Authenticating Digital Photographs as Evidence: A Practice Approach Using JPEG Metadata

When I first contemplated this article, the issue of authenticating digital photographs for evidentiary purposes seemed fraught with arcane complexity and uncertainty. However, that�s not actually true in practice. In fact, the metadata stored in any JPEG or RAW photographic file may help you authenticate that photograph and contradict the popular view that digital photographs can be easily and undetectably altered. Certainly, it is harder to undetectably fake a print made from a film negative than a digital file, but current digital cameras contain enough non-evident metadata to detect most alterations.
In this article, I will discuss some general evidentiary issues that arise when a party wishes to use photographic evidence, propose a standard procedure to ease the authentication of your own digital photographic evidence and offer a test as to whether or not you are receiving discovery of authentic photographic evidence from the other side. Surprisingly, this may be as easy to do with digital photographs as with photographic prints made from film negatives.

Photographic Authentication and Admissibility: Evidence Rules 901 and 1001

Under Evidence Rule 901 and its state analogues, photographs are typically admitted as demonstrative evidence to illustrate testimony. When used purely as demonstrative evidence, legal issues regarding authentication and chain of custody are somewhat relaxed so long as a competent witness can testify that the photograph fairly and accurately depicts the scene about which he or she is testifying. In these situations, it is generally not necessary that the authenticating witness be the same as the photographer or as a competent person who observed the making of the photograph. United States v. Clayton, 643 F.2d 1071, 1074 (C.A. 5, 1981. Videos are typically authenticated in the same manner as a still photograph. Saturn Manufacturing, Inc. V. Williams Patent Crusher and Pulverizer Company, 713 F.2d 1347, 1357 (C.A. 8, 1983). I will illustrate some portions of this discussion using a series of decisions by the Alaska Supreme Court whose evidentiary rules and interpretations typically closely follow majority federal views.
Under Evidence Rules 1001 through 1004, an �original� document (including a photograph) is required to prove the truth of the facts for which any document is offered. However, over many years, the definition of an �original� has been greatly expanded, particularly with regard to electronically stored information, and the requirement for an �original� is honored more in the breach than to the letter. Indeed, duplicates, including electronically made prints or digitally identical electronic file duplicates, are typically admissible to the same degree as an original document unless admitting the duplicate would prove inaccurate or unfair.
Authentication requirements are somewhat stiffened where there is a strong argument that a photograph does not accurately reflect the scene or that the use of a duplicate is inaccurate or unfair. Generally, a trial court�s admission or exclusion of proffered photographs is reviewed under an abuse of discretion standard. (See End Notes 2 and 4, below) Common sense, a reasonably objective evaluation of your intended use of the proposed photographic evidence and some trial experience are usually an adequate guide to the allowable demonstrative or evidentiary uses of a photograph. A trier of fact�s evaluation of �non-demeanor� evidence like photographs (as contrasted with live witness testimony) is theoretically subject to a less deferential standard of appellate review but this more stringent approach is often not strictly applied. (See End Note 5, below). However, when photographs are to be used as the basis for expert witness testimony or to actually prove the existence of an allegedly depicted condition, then they will be held to a higher standard and you will need to be much more cognizant of subtle technical and photographic parameters.

Admissibility of photographs varies, depending upon the evidentiary context and the purpose for which a photograph is offered

Courts are usually willing to tolerate some inaccuracies in a photograph so long as these are explained to the trier of fact so that they may be taken into account. However, where a photograph is used as a basis for establishing critical ultimate facts or as the basis for expert testimony, courts are less willing to overlook major gaps. For example, the Alaska Supreme Court, in Kaps Transport, Inc. v. Henry, 572 P.2d 72 (Alaska, 1977) stated, at 572 P.2d 75-76, the majority rule:
"That there are inaccuracies or defects in the photograph does not necessarily render it inadmissible as long as there is an explanation of these imperfections so that the jury is not misled", quoting Riksem v. Hollister, 96 Idaho 15, 523 P.2d 1361 (1974) and Southeastern Engineering & Mfg. Co. v. Lyda, 100 Ga.App. 208, 110 S.E.2d 550 (1959).
However, in Kaps, the Alaska Supreme Court excluded the photograph in question because the defendant�s accident reconstruction expert was attempting to use the photograph, in conjunction with a reconstructive technique known as perspective analysis, to establish how far across the highway centerline the Plaintiff had alleged strayed. In order to use a photograph as a basis for perspective analysis reconstruction, the focal length used to take the photograph and the conditions under which the photograph was taken must be known with a substantial degree of precision, which the Defendant could not show. In this case, the photograph was to be used to provide actual data about the accident scene rather than merely illustrating the area. Hence, it was subject to a more rigorous authentication process which it ultimately failed.
Similarly, where a photograph is offered to prove that some condition did not exist, a court will look closely at the time frame when a photograph was purportedly taken but still use a common sense case by case analysis. For example, if a photograph is offered of a criminal defendant�s hands purporting to show that there was no gunshot residue, and then the offering party must establish that the photograph was taken at a time when gunshot residue would still be apparent. Absent that showing, the photograph may not be admitted. On the other hand, where direct evidence of a condition provided by an otherwise authenticated photograph is only one link in a logical fact structure, the photograph will likely be admitted to prove the depicted condition.
In cases where there is sufficient countervailing testimony, the admission of photographs with a shaky time frame may be harmless error. For example, the Alaska Supreme Court refused to reverse a verdict despite the trial court�s admission into evidence of the defendant highway department�s arguably inaccurate photographs that purported to show that an accident site was well-sanded despite the Plaintiff�s contrary contentions. The time frame when these photographs were taken, relative to the time of the accident, was never precisely established but was sufficient contrary testimonial evidence by the investigating State Troopers actually at the accident establishing that photographs were inaccurate and that the road was poorly sanded. Hence, admitting these allegedly misleading photographs with an imprecise time frame was harmless error.

Metadata and Discovery

The proposed amendments to Civil Rules 26 and 34 effective as of December 2006 further broaden the definition of what constitutes an �original� document and expand both the discovery and usefulness of documents whose original format is electronically stored information (ESI). Indeed, the proposed new discovery amendments seem to require, as a default position, that any discoverable ESI be produced upon request in its �native format,� i.e., production of Microsoft Word documents should include identical copies of the original .doc format files, production of photographic documents should include digitally identical copies of the original JPEG format files, etc.
It appears that the new federal rules will also generally require the production of an electronic file's "metadata," that is, the electronic file�s internally stored information about the creation and alteration of any electronic file. Although privilege reviews will become more complex when you must produce metadata, the production of document metadata may be the most readily available, although not entirely fool-proof, means of determining the authenticity or alteration of electronically stored photographs. Most native format files, including the JPEG photographic files made by most modern digital cameras, will include the document�s metadata unless it is rather obviously stripped out with one of the numerous metadata removal programs now on the market.
I suggest that removing metadata from photographic files produced by non-attorneys and by expert witnesses is inappropriate in most instances except when there are obvious privilege issues. Consider, for example, how untrustworthy a photograph would be if the internal metadata showing the camera model, focal length and original date/time stamp is later removed. Concerns about its accuracy and authenticity would be very high, particularly if the metadata would have shown use of a camera that the witness did not own or that the photograph was taken on date or time remote from the pertinent time frame. On the other hand, if you know how to use a photographic file�s metadata, then you can use it to authenticate your own photographs for evidentiary purposes and possibly impeach the other party�s exhibits.
credits;http://apps.americanbar.org/lpm/lpt/articles/tch06061.shtml Print Page

No comments:

Post a Comment