Today we had a visit off a Crime Scene Investigator called Keith Smith when he talked about his job description and what he has to do when going into a crime scene.
Crime Scene Investigators mostly photograph crime scenes where a burglary has taken place, as well as fires and peoples injuries. But they sometimes investigate deaths and CBR n-scenes (e.g. after anthrax poisoning etc). All crime scenes require photography.
He told us that you can only study the CSI course at Durham, and the first 4 weeks are on photography. He uses a Nikon D 200, a 105 lens, no filters, multiple flashes, and a standard tri-pod. 3-D photography is not widely used due to lack of funds and the only available ones do not have good software so do not produce good quality images. However 3-D scanning of crime scenes will be used in the future.
While photographing a CBR n-scene they use underwater cameras so it can be cleaned in bleach – as everything is decontaminated after leaving a crime scene, and they only have 20 minutes to take the photos.
He explained step by step what you would have to do when you enter a crime scene. First you photograph whole place, then anything of interest is given a number (i.e. ‘exhibit 1’) then each exhibit is photographed to build up the picture.
Flat, plain white light, no central beam.
Finger print powder, a brush with a magnet
Sellotape to pick up fingerprint – to be stuck on some Perspex.
Photographing footprints in sand.
In photographing a footprint you had to photograph it four times in different ways, each way with the light shining on it at an angle from one corner, so that four angles have been photographed and the shadows in the footprint have been captured at every angle. So this will give a clear image.
My job in the team for this was to be in charge of the light, moving it around while Nathan photographed the footprint. In the exercise we had to wear special clothing, covering all our body and feet. We wore plastic gloves as well so we did not contaminate the footprint (or ourselves). I learned that moving the light around gave the image depth – it was not flat. We had to place rulers next to the footprint so the size could be gauged.
Taking a photo of a shoeprint underwater
For this activity I was working the lights again. The camera had to be directly above the shoeprint and this was hard to arrange as the camera and light could not go under the water and the surface of the water had to be really still to get a good image. In real life a shoeprint under water could be washed away really quickly. It could be night time as well, and the darkness would make this type of photograph very challenging.
Developing our own fingerprint
pick up a glass bottle so that your print is left on it, run the Ultraviolet powder over your fingerprint with the tip of the brush, shine Ultraviolet light on it and photograph. This photograph was done with bright orange fingerprint powder. It was easy to see the print and I held the light really close to the bottle to help the photographer. The print was put on a curved surface of the bottle and it was important to position the bottle and the light carefully to take an accurate image.
Put on gas mask and gloves. Go into a dark room with your team, treat it as a crime scene. Your only light is from your torch. Find the bottle which has a print on it and dust with magnetic powder. Lift fingerprint off using the tape. Put a bite mark scale on it, put it on a flat surface, take the photo, read instructions to the person in your team with the camera.
This was the hardest task to do as we entered the room in the pitch black. There was only one small light source and we were unsure where the bottle was. We took a photograph of the bottle in its place, then again once the magnetic powder had been applied. Then we had to start putting the tiny light source on the image of the fingerprint to take a scale photo with a ruler. We were wearing protective clothing and it was very hard to move with the precision required. Getting the photo with the ruler next to the fingerprint was tricky and it was vitally important not to destroy and evidence. We had to use sticky plastic to get the DNA off the fingerprint. Pulling the tape backing off was very difficult in the protective gloves, especially under the pressure of time.
Photograph a fake injury
In this task Craig was the model and we decided to give him a ‘black eye’. I painted his face to make it appear that he really had a black eye and Nathan photographed his face. For this we used a flash and put him against a white background. We took photos of front and side views, being careful not to create too much shadow as this may make his bruise appear worse and this could affect things in court. It was important to make the injury look as much like the naked eye as possible.
Overall I really enjoyed this day as it really opened my eyes and was very exciting finding fingerprints. I would like to look at this further but I am unsure who I would feel about having to photograph a dead body. I think that this is a very hard job to do as if the photographer slips up in any way at all, the whole court case could be affected. At the same time, your work can get a defendant sent to prison for the right reasons.
I learned how important it is to get accurate images and as much information as possible. The photographer has to follow procedure to protect evidence so the jury and lawyers can see it and get the story straight in their heads. It is important to have a good eye as the photographer has to find the evidence. There is a skill involved and the police officers do not tell you what to photograph; the crime scene photographer has to find the evidence as well as record it photographically as accurately as possible.