Crime Scene Photography

CRIME SCENE PHOTOGRAPHY by Steve Pearson

Crime scene photography, like any other form of 'once-in-a-lifetime' photography has to be done right the first time. There is no room for errors, for guessing or omissions. It is imperative that the crime scene is recorded accurately on film in the first instance, because it will be too late to go back later. As a crime scene examiner or as a designated crime scene photographer, it is your task to make that accurate record for a number of reasons. Perhaps the most important reason is to eventually transport judge and jury to the scene many years later, to show them what the scene looked like at the time of or immediately after the crime was committed. It may be no more than a handful of photographs of a simple break and enter offence. The attention to detail in that instance should be no different to that paid to a major incident such as a murder. The only difference will be the volume of the work you do. Other reasons for recording a scene are to provide Police with a photographic record to assist them in their investigation - especially if it is unsolved, to reveal any latent details at the scene and to enhance microscopic details which are not readily visible to the naked eye.

1.1 INTRODUCTION

In writing this chapter, it is assumed that the reader is an accomplished crime scene examiner. What I will outline are the basic requirements and methods to be applied to crime scene photography which will stand any forensic photographer in good stead and enable him or her to procure, prepare and present to a court of law a photographic record which accurately and objectively describes the crime scene attended.

2.1 THE CAMERA

There is an old saying which goes, “A tradesman is only as good as the tools he uses.” This is very true when it comes to crime scene photography. Without good, well-maintained photographic equipment you will not be able to do your job to perfection. You need modern, state-of-the-art camera equipment which is capable of being used every day for hours on end and which can handle the odd bump. Advances in digital photography are occurring at astounding rates and digital cameras are slowly but surely making inroads to forensic photography. No matter what medium you use however, the methods and procedures adopted to actually photograph a crime scene do not change. The minimum requirement for many years has been, and for a lot of years to come will be, a 35mm SLR camera with a metal body. It is on that basis that the following is presented..

2.2 THE LENS

It is the quality of your lens which will govern the quality of your photography. For crime scene work you will need more than a standard lens. The minimum requirement is a wide-angle lens of at least 28mm focal length; a macro lens of around 50mm focal length which will give you 1:1 magnification and possibly a medium telephoto lens of 135mm focal length. If you are looking for greater magnification than 1:1 with your macro lens, you will also need an extension tube. Your department may also be able to supply you with a zoom lens in the range of 28-105mm which can take the place of both the wide-angle and the medium telephoto lenses.

2.3 FLASH EQUIPMENT

Not every crime scene you attend will be as easy to photograph as an everyday, landscape shot. There will be indoor scenes, underground scenes, night scenes, outdoor scenes with heavy contrasts between light and shadow and any one of a myriad other situations which demand additional lighting. It is therefore essential that your camera is coupled with an efficient flash unit with a high output, which can be dedicated to the camera. Gone are the days of guessing lens apertures and flash guide numbers. Today's modern cameras and dedicated flash units not only take the guess work out of camera and flash settings, they also calculate the scene presented to them in less time than it takes to press the shutter release button - and deliver an optimum image to the operator.

2.4 ESSENTIAL ACCESSORIES

No crime scene photographer would consider throwing such valuable camera equipment onto the back seat or floor of a vehicle in between jobs. This valuable equipment must be looked after at all times, and when it is not being used should be stored and transported in a sturdy, air-tight camera case. Also, no crime scene photographer worth his salt would consider a camera outfit complete without a sturdy tripod. The camera's power requirement must be kept in mind, with spare fresh batteries always part of your equipment. This also applies to the power supply for your flash. Other items essential to the crime scene photographer are scales and graphs, a grey card and a colour chart.

2.5 FILM

The quality of film available today is constantly improving. Film technology is such that image quality produced by fast films is superior to that of the slower films of 10 or 15 years ago. The grain detail of today's ISO400 colour negative film is finer than that of yesteryear's ISO100 film. Many Police departments today have moved right away from monochrome (black and white) film and now photograph all their crime scenes in colour - including fingerprints. The Courts too, have come to expect colour photographs. Jurors live in a colourful world. They have colour televisions, colour photographs of the family on the wall at home and they are bombarded daily with colourful images from bill boards and magazines. Why take them on a nostalgia trip, and put crime scene photography back 50 years by producing monochrome photographs at Court when there is no need to? Of course there will be times when monochrome film will be used, especially for technical applications, and there it comes into its own. My personal preference for crime scene photography is ISO400 colour film. When I have to use monochrome film I use ISO125 which I rate at ISO80 for greater image contrast. Reversal (slide) film also has its place in crime scene photography, especially for illustrative, demonstrative and lecture purposes. Whilst it is not always possible to photograph a crime scene with both negative and reversal films, the copying of photographs onto slide film is a simple procedure.

3.1 TECHNICALITIES

3.1.1 CORRECT EXPOSURE

Again, in assuming the reader's expertise in crime scene examination and forensic photography, I will only briefly touch on the essentials of obtaining the optimum image. It is important to keep in mind the need for pin sharp images coupled with maximum depth of field. Both these aspects are achieved by careful selection of aperture settings, and the correct selection of complementary shutter speeds to obtain the correct exposure. Bear in mind, that whilst negative film (both colour and monochrome) has a fairly wide exposure latitude which will compensate for 2 or 3 stops over-exposure or under-exposure, there is nothing like a good set of correctly exposed negatives to produce a perfect set of photographs.

3.1.2 FLASH MANIPULATION

In paragraph 2.3 I touched on the need for a powerful flash unit for your camera. I referred to the use of a dedicated flash system which in effect works in tandem with the camera (their electronic circuits are on the same `wavelength') to give you optimum flash exposure photography under most conditions. There will be times however, when you will have to take charge of the flash unit and dictate to the camera and its film how much light you are going to apply to a particular scene, and how you want it recorded on the film. If you are photographing the remains of the interior of a burned-out building for instance, the need for flash lighting will be vastly different to that required to photograph a snow scene in daylight. The black of the burned-out building will `soak up' the light from the flash and there will be nothing left to record on the film. It will be necessary for you to switch your camera and flash to manual, and allow 2 more stops over-exposure on your camera than the exposure indicated on your flash. For instance, if you set your flash for an exposure at ƒ11 then you will have to set the aperture of your lens to ƒ5.6 to compensate for the light which is `soaked up.' Conversely, if you are photographing a scene in snow and it is necessary to use flash to highlight some details, you may have to stop down your lens aperture by 2 stops to overcome the brilliant combination of flash and snow glare which could wash out your image. In other words, in extremes of conditions don't allow your camera and flash to do the work. Both are calibrated to work in a `normal' world where everything is average. That is why the photographic industry works on the standard 18% reflectance grey card which is technically in the middle between pitch black and brilliant white. If you do not have a grey card amongst your equipment, then get one. It is one of the cheapest aids for determining exposures that a photographer can own and use.

3.1.3 PAINTING WITH FLASH

All flash units, regardless of how much light they put out when fired, suffer from the same problem - light fall off. If you are aware of the inverse square law relating to flash output, then you will know that the furthest objects from the camera and flash receive less light than the ones closest to the camera. They therefore show up darker in your photograph than those closer objects. When photographing a large scene at night, especially outdoors, you can supply flash light to all of the scene and make it appear like daylight by using a simple technique called `painting with flash'. All this means is you have your camera mounted on a sturdy tripod, and with a suitable aperture selected (say ƒ4 or ƒ5.6) you focus your lens, set your shutter speed to `B' and lock the shutter open. You then set about walking around the scene with your flash unit set for the same aperture (ƒ4 or ƒ5.6) and fire the flash off manually at objects in the scene which you want to appear correctly exposed in your photograph. It is important not to stand between the flash and the camera and so create multiple silhouettes of yourself throughout the scene, and not to fire the flash straight at the camera. It may be necessary between flash firings to have an assistant cover the front of the lens with a dark object such as the inside of a Police hat to avoid `hot spots' such as street lights burning bright areas into your photographs.

4.1 PHOTOGRAPHING THE CRIME SCENE

4.1.1 BASIC REASONS

There is a number of reasons for photographing a crime scene. The most basic of those reasons is:

• To record the scene and associated areas,

• To record the appearance of physical evidence as first encountered,

• To provide investigators with a photographic record of the scene to assist them with their investigations, and

• To present the crime scene at court for the edification of judges, juries and counsel alike.

4.1.2 THE CRIME SCENE PROPER

It is important before entering and photographing a crime scene that you talk to investigators at the scene and formulate a plan of attack. In the majority of cases, especially with indoor scenes, there is no need to rush in, to take a dozen quick photographs and then leave. Outdoor scenes will be governed by terrain and weather conditions. You must liaise with investigators, find out exactly what they want photographed, know what they are investigating, and be prepared to use your expertise to record the scene accurately. It is always possible that your trained eye will see something the investigators cannot see. Bring it to their attention and record it.

4.1.3 THE TECHNIQUE FOR GOOD COVERAGE - THE BIG PICTURE

Photographing of a crime scene should start with location shots, which are wide-angle photographs of the general crime scene and surrounding areas. They will present a big picture of the overall scene to show its layout, and to show the relationships between various pieces of evidence at the scene. This may involve aerial photographs from an aircraft, from some other elevated advantage point nearby, or simply general shots from a distance. If the scene itself is an indoor one, I work on a minimum of 10 photographs of a room using a wide-angle lens - one from each corner looking diagonally to the opposite corner (4); one from the centre of each wall looking directly to the centre of the opposite wall (4); one from near floor level at one end of the room looking up to the ceiling (1); and one from the same end of the room near to ceiling height looking down to the floor of the room (1) giving the total of 10 photographs.

4.1.4 THE MID-RANGE PHOTOGRAPHS

The next set of photographs should be your mid-range shots.These show the relationships of specific items of evidence to each other and to the scene proper. They should be photographed from normal viewing height, the same perspective any person in the room or at the scene would have when walking through them. Remember, your photographs will eventually be viewed by a judge or a panel of jurors, and they must be able to relate to the scene easily, with no distortions or confusion.

4.1.5 THE CLOSE-UP PHOTOGRAPHS

Generally, the final series of photographs will be close-ups to show details of important pieces of evidence which you have already identified in your mid-range photographs. Items with which relative sizes are important should be photographed with and without a scale. The item should be firstly photographed as located, then photographed again including the scale. It is important that the scale is placed on the same plane as the item, and that the film plane is parallel to the scale.

4.1.6 IMPORTANT POINTS TO REMEMBER

• If you have a crime scene which is not confined to one area, photograph it progressively by doing a `walk-through'. Always link your photographs by having some identifiable object in one photograph visible in the next photograph, and so on.

• Be careful where you step and what you touch. Do not destroy any evidence such as shoe impressions, blood stains or fired cartridge cases as you are photographing.

• If an object was moved prior to your arrival, don't try to replace it or have someone else replace it in an effort to reconstruct the scene. Photograph the scene as it presents itself to you. If an investigator asks you to photographs a particular aspect of a scene after an item has been replaced, make a record of it in your field notes.

• Don't be rushed by an investigator. He or she has a job to do - and you have yours. Conduct your photographic examination systematically and objectively. In serious and major crime scenes record everything, regardless of its apparent irrelevance. Many a crime has been solved a long way down the track, thanks to photographs of objects in scenes which at the time had no apparent relevance. Adopt a policy of total disclosure and you can never be criticised for over-photographing a crime scene. Remember, film is cheap.

5.1 SPECIFIC CRIMES

Each crime scene has its own particular features, and the type of photography required at each scene will be determined by those features.

5.1.1 HOMICIDE

Murder has been called the most heinous of crimes - the taking of another human life. It abhors all humanity and demands swift and satisfactory resolution. For that alone, the photographing of a murder scene will be a detailed one. The same procedures as outlined in 4.1 above are important. Perhaps the most important `items' at the scene will be the victim, injuries and any weapons located. It will be important to photograph any signs of activity prior to the murder; any evidence of a struggle, or of forced entry if an indoor scene; and the views from the positions any witnesses had of the crime. You will usually have to attend and photograph the ensuing autopsy, where as well as taking photographs for your own information, you may be asked by the attending pathologist to take photographs of anatomical significance for his information.

5.1.2 SUICIDE

When attending a suicide or any other deceased for that matter, and there is some doubt as to the circumstances of the death - treat it as a homicide. Film is cheap, and if the suicide should turn out to be a murder you have covered it fully. Don't think it cannot and will not happen. History is full of murders made to look like suicides.

5.1.3 ASSAULT

Assaults and other injury crimes firstly require a general, overall photograph of the victim prior to detailed photographs of injuries. An assault victim can be photographed like a mini crime scene, with general (big picture) photographs, mid-range and close-up. When photographing bruises, bites marks and other injuries close-up, use a scale to show the sizes of the injuries; photograph at 90 degrees to the injury to avoid distortion; and use a small aperture especially on curved surfaces such as an arm or finger to increase depth of field and so ensure the entire injury image is sharp.

5.1.4 STRUCTURAL SCENES

Scenes of building fires, building collapses or other structural events, both externally and internally, should also be photographed using the `big picture, mid-range and close-up' principles Always ensure your own safety and the safety of your valuable equipment.

5.1.5 MOTOR VEHICLE CRASHES

Scenes of motor vehicle crashes, and for that matter scenes involving crashes of any kind - be they motor vehicles, aircraft or even trains - should also be photographed using the `big picture, mid-range and close-up' principle. These photographs must show the relationships of each vehicle to the other; the view each driver had on approach to the point of impact; the direction from which each driver came; debris and marks on the roadway; views from the points witnesses observed the crash at their eye levels; technical photographs showing damage to the vehicles; and where necessary detailed photographs of physical evidence to identify hit and run vehicles. The damage to a vehicle must be photographed from at least two opposing diagonals and through the two axes of the vehicle, as a minimum. Flash should be used to fill in shadows within damaged areas. Remember, despite the terrain and the positions and angles of vehicles, to keep the camera horizontal at all times. Liaise with the crash investigators and be guided by what they require of you.

5.1.6 BREAK AND ENTER OFFENCES.

Again the `big picture, mid-range and close-up' principle applies. Close-up photographs will include tool marks, shoe impressions, fabric impressions, fingerprints and other trace and physical evidence. These will all include a scale, and fingerprint examinations and photography will be carried out according to laid down procedures.

6.1 TRACE EVIDENCE

6.1.1 SHOE AND TYRE IMPRESSIONS

The same principle applies as in general crime scene photography, with the `big picture' photograph showing where in the scene the impressions is located. This can be indicated with a marker alongside the impression, which is left in position when the mid range and close up photographs are taken. With these larger items of trace evidence I maintain a standard lens setting when photographing them, which makes it easier to relate sizes when viewing or enlarging photographs for comparison purposes. Of course a scale is always included in the photograph as well as an identifier with the date, location and my initials thereon. It is important to keep the film plane of the camera parallel to the surface bearing the impression. It is equally important to use an oblique light source to reveal the detail of the impression. When using flash in this way on an impression which is outdoors and in sunlight, cast a shadow across the impression to enable the flash to create a greater contrast and so reveal the detail in the impression. A shoe impression can be photographed on one film frame. A tyre impression however needs numerous frames which must overlap, and here it is important to have a measuring tape alongside the impression to show the scale and to enable the photographs to be joined if necessary. A standard 50mm to 55mm lens should be used for impression photography as a wide-angle lens will give unacceptable distortion to the impression.

6.1.2 BLOOD SPLASH PATTERNS

Photographs of blood splash patterns, whether they be on a floor, on a vertical surface such as a wall or even overhead on a ceiling, must be photographed with the film plane parallel to the surface bearing the stain. A scale must be included on the same plane as the surface. Of course, like any serious crime scene, general location photographs must be taken to show the positions of the blood staining at the scene.

6.1.3 MACRO/MICRO PHOTOGRAPHY

Apart from 1:1 and 5:1 fingerprint photography other detailed photographs are often required of tool marks, serial numbers, pieces of jewellery and the like. The focusing of a lens so close to small objects, especially when an extension tube is used, requires the use of the smallest possible aperture in the camera lens to ensure maximum depth of field and clarity of detail of the item being photographed.

7.1 ALTERNATE LIGHT SOURCES

Many lighting sources are available in forensic photography, apart from ambient daylight and electronic flash. They include infra-red, ultra-violet, laser and the `Polilight'â. Each has its own applications and limitations. Their uses are mainly restricted to the crime laboratory, with the exception of the `Polilight'â which is portable and can be taken to and used at crime scenes to reveal and enhance latent trace evidence such as fibres and body fluids. Photographing of such trace evidence requires the use of barrier filters, and descriptions of techniques and applications which are too detailed and comprehensive to report here.

8.1 SUMMARY

Be in the habit of ensuring that all your camera equipment and accessories are in top condition, and will enable you to attend and photograph crime scenes with the knowledge and confidence that each photograph you take will be as technically perfect as possible. Be critical of your own work and where you can, improve on it at the next scene you attend. Treat every scene with the same degree of attention to detail, with the same objectivity, and make the camera an extension of your eyes and your analytical mind. By being so thorough and objective, your reputation as a crime scene examiner and forensic photographer will flourish, and the results of your work will for many years be accredited as playing key roles in the successful conclusions of many investigations.

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Physical Evidence Unit

Forensic Services Group

Crime Scene Section

Police Station

DUBBO NSW 2830

Email: lightforce@ozemail.com.au