As a lecture today, we were joined by a Forensic Photographer who spoke about what their job entails.
Forensic photography is taken on behalf of courts and are split between different shifts of which for the photographer, Smith is 7am til 10pm. With an on call system throughout the night.
Here they usually cover burglaries as the regular option.
- Domestic – Home
- Commercial – Business
- Motor vehicles
Covert – Don’t want people to know.
This is so the evidence can be taken to court to explain to the people there was has been witnessed and how the evidence speaks about what took place and how it shows that the person in trial is the culprit.
Types of Evidence
The types of evidence found are:
DNA (Deoxyribonucleic Acid)
Which due to Locards principle of “Every contact leaves a trace” so a crime scene is something left behind after a crime. Which helps create a timeline of contact or explains if something/someone was there.
Bertillion created a standard identification so to create a descriptive database for what people looked like through their measurements and based on their appearance instead of only having an image available. This though was later changed to be a finger print database due to fingerprints being unique to each individual. He was though also the first person to use a camera in forensics as it was seen as being quicker than drawing and was more reliable.
When capturing a crime scene though they work in and around the area so to walk the jury around the scene, seeing what the forensic photographer saw. These are as:
Entirety – Including background – over all shot – setting the scene
Overview – Zoom into the crime scene – identify all evidence
Context – Separate evidence images – scaled and labelled
To capture an image you have to move the light source across it in 4 ways of each angle. So that the areas are all lit to show the full detail then are overlapped to give a full image and creating a silhouette. As the photographs have detail, making the impressions in the image clearer. To light the evidence a colour wheel is used so to contrast for example a blue object would be lit in orange.
For this the lights are UV, Infrared etc. This is due to body fluids fluorescing. Where the light is painted with through long exposures and walking over the scenes manually with a torch on top of using depth of field.
With postmortems a CSI would create a chain of evidence. Detailing the key information, who the officer is, where found and sealing the evidence so it can’t be tampered with. Alongside documenting it to show where the evidence is found and that no one except the investigation when collecting it has touched the item. The evidence is also given a chalk outline to mark where it was found.
To overcome the problems the CSI’s use light of which they use a key white balance that suits the area best.
Plus has a special outfit for the scenes. These are the three outfits.
These focus on the shadowing of fire to show the point of ignition. Showing where a fire started and the route it took to spread out.
These have to be peer reviewed.
Road Traffic Accident’s
These look at whether the scene is seen as suspicious.
Along with showing signs of whether stolen, a death has occurred, a crash etc.
Difficulties with Crime Scenes
When taking images of scenes there are difficulties. These can be the location as the scene of crime officer will need to get their camera in the scene with out disturbing the evidence or harming themselves. Which if on a smaller scale can be difficult. However, on a large scale is also difficult as it means if say a mansion was on fire then they need an over view like with all investigations. Entailing the photographer to have to use a crane to get the full image.