What is forensic photography?

Forensic photography documents the physical appearance of a scene soon after a crime, accident or failure occurs then presents this information to the justice system, and does this objectively. (Ref. 1)  These are the main goals.

The forensic engineer also uses the photographs to study the scene again later in his role explaining the technical issues and the cause of the incident to the justice system.  Others also learn about the scene from the photographs.  It is an exacting speciality like all the technologies involved in forensic work.

Police crime scene identification unit

I was reminded of this when I toured the Halifax Regional Police Crime Scene Identification Unit recently.  David Webber, the forensic photographer with the unit, showed me around.  I had met David earlier at a social function hosted by the police department for the Victim Services Unit.

There are 13 people in the identification unit specializing in a number of technologies.  “Lifting” and analysing finger prints from surfaces and trace fluids from clothing are two the public is familiar with.  David does the photography.  We had a difficult time getting together because he was being called out to one murder scene after another over a period of a week or more.

I didn’t get out to a crime scene but did see how David presents his photographs in a book for use by the justice system.  There is nothing in his presentation or the captions – just a single number, to sway what the justice system and others might see in the photographs.

In civil litigation, the photographs could be of a scene where a personal injury accident or an engineering failure occurred, or where an incident was re-enacted by a forensic engineer.

Almost all photographs are taken at or near ground level – what we call terrestrial photographs in engineering.  But you are certain in future to see low level, oblique aerial photographs taken with cameras fitted to drones.  I use this technique now.  The police Identification Unit are looking at using it.

Uses of photographs in court

Photographs can be used in court for illustrative purposes, if admitted by the judge, to: (Refs 1, 2)

  1. Support, corroborate and explain the evidence of witnesses,
  2. Supply relevant detail in the appearance of objects described in oral testimony,
  3. Reveal steps taken by witnesses to arrive at their opinions, and,
  4. Affect the credibility attached to a witness’ testimony. (Ref. 3)

A witness uses photographs to illustrate what was seen and done during the forensic investigation and the evidence that was collected.

A photograph can also be used as a silent witness, if admitted, as,

  1. Substantive visual evidence.  The photograph is allowed to “speak for itself”.

There is no witness, the photograph stands alone, a silent witness.

Allowing photographs into court

A judge will allow photographs to be tendered as exhibits and admitted as evidence in a Canadian court if the following test is met: (Ref. 4)

  1. Photographs must be relevant, that is, material to an issue at trial,
  2. Also, accurate in truly representing the facts,
  3. Fair and absent of any intention to mislead,
  4. Verifiable on oath by a person capable to do so,
  5. And if their probative value exceeds their prejudicial effect.

Put another, less comprehensive way, photographs for the court must be: (Ref. 1)

  • True and accurate representation of the subject
  • Free of distortion
  • In proper perspective

Forensic photography as high technology

Getting a true, accurate, distortion-free perspective of the scene is where photographers like David Webber and their knowledge, skill and objectivity come in.  It’s high technology when you realize how many decisions must be made for every click of the shutter: (Refs 1, 5, 6)

  1. Angle to shoot from,
  2. Closeness to the subject – distant, medium distant, close up, detail,
  3. Lighting – natural or artificial,
  4. Film speed,
  5. Lens – normal, wide, telescopic,
  6. Aperture,
  7. Shutter speed.

Then another series of decisions must be made when presenting the photographs objectively to the courts.

That’s forensic photography in a nutshell.

References

  1. Tupper, Allison D., Use of Photographs at Trial, Chap. 15 in The Expert: A Practitioner’s Guide, Vol. 1, Matthews, Kenneth M., Pink, Joel E., Tupper, Allison D. and Wells, Alvin E., Carswell Publishing 1995
  2. Goldstein, BA, LL.B, Elliot, Visual Evidence, A Practitioner’s Manual, Chap. 2, Carswell, 1991 as referenced in Matthews, Kenneth M. et al
  3. Scott, J. D., Motion Picture and Videotape Evidence (November 8, 1974), Ontario Crown Attorneys Bulletin and Benson and Hedges (Can) Inc. v. Ross (1986), 58 NFLD. and P.E.I.R. 38 (P.E.I.S.C.) as referenced in Matthews, Kenneth M. et al
  4. R. v. Creemer (1967), (1968) C.C.C. 14 (N.S.C.A.).
  5. Wikipedia, May  8, 2016
  6. Kook, Frank, photographer, Halifax, May 10, 2016

 

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