Crime Scene Investigator And Evidence Collection

Essay, Pages 8 (1962 words)

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Introduction

As a trainee CSI I will be exploring the procedures used to preserve, collect and record forensic evidence to ensure contamination is limited. From the police report I already know that Elise phoned the police because has seen people entering her neighbours back garden late at night as Mavis which is whose house is allegedly be seen with people late at night. She is currently in hospital and going into a care home so as a CSI my predictions from the crime scene and the police report is that Male or female who is a drug addict and an alcoholic has broken into mavis house and decided to live there for a while.

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This suggests that the perprator may know Mavis which is why they have decided to stay at her house as they know she isn’t coming back, as suggested I know it is a break in because from the crime scene the point of entry was the window and they broke in through there leaving glass and mud on the windowsill.

Getting the evidence, preserving it and collecting it is crucial for this case as from the police report it isn’t very reliable as when interviewed Elise got confused as her eyesight is very good so she doesn’t know how many people are there so the description is very limited and lacks in description which means this case wouldn’t stand up in court so it’s all down to the CSI with the evidence and analysis.

This involves providing the restriction of access, search patters, documenting trace materials, limiting contamination, observation and recording. The continuity of evidence is very important during this case and will be shown throughout this report describing the whereabouts and how everything is handled before it is due to be presented in court.

Restriction of access

During the first and second part of the case it is the initial response stage where an investigator is sent to the scene of the crime and is where the witness so Elise in this case will report what has happened and locate information where they will then call the CSI team. As a crime scene investigator I believe when you get to the crime scene it is known as the ‘golden hour’ where there is lots of important elements for the investigation such as the evidence wont have been disturbed, witnesses and criminals may still be near. This is because for me to do my job properly I believe that cases that are pursued immediately are better at getting facts and preserving the evidence. PPS should also be adopted which is the preservation of life which wouldn’t be needed in this case because there was no body found at the crime scene, then it would be preservation of the scene so looking around at the evidence, thinking about what could have happened and the possible entry and exists. Then the last one is securing the evidence so if it is windy or raining if the crime scene was outside then putting a tent or protective layer over evidence so it isn’t ruined, it also involves finding the evidence, packaging it and labelling it.

The restriction of access involves calling the crime scene coordinator which are specialists police officers that deal with the crime scene and then the scientific support manager which is in charge of minimising the opportunities of cross contamination. My role is also to apply this by reducing cross contamination which is where microorganisms or bacteria are transferred from one substance or object to another because if this happens it can jeopardize the case. The log of CSIS who enter the crime scene and leave it should also be recorded such as the scientific support manager, scene of crime officer, other police officers, crime scene manager and coordinator and first attending officer. This is important because its stops people from coming in who shouldn’t and also keeps a log of people who have entered the crime scene because it something that has been found that has gone wrong at the crime scene then people may know who it could be and you need to know for prosecution and defence reasons. It is also to reduce the amount of contamination because the more amounts of people the more there could be. The crime scene should be cordoned off using crime scene tape that is bright yellow and police officers should be on guard as this is shown in the report [1] but this should be done first before the security log.

Risk Assessments

Risk assessments are carried out to make sure people are safe and that contamination is limited, as health and safety awareness is very important. As a forensic scientist I am always exposed to lots of health risks, this is why measure such as health and safety risks are taken out to stop accidents. A risk assessment includes identifying potential risks, how to prevent it from happening and the consequences. Health and safety is very important at work especially when dealing with crime scenes, CSI need it when handling substances as they may be corrosive or toxic.

What is the hazard? What harm and who? What are you doing already? Further prevention. Broken Glass from the window. The harm that can happen is to the analysts and people at the crime scene. The broken glass can mean that they can cut themselves. Wearing plastic rubber gloves. If you do cut yourself with the glass then you should apply pressure and bandage it up.

Sharp Scissors It is a sharp object so can cause wounds to the skin and can lead to infection. Wearing protective gloves and not touching evidence so no harm can be done. You should bandage it up and depending on how serious it is then go to hospital. Drug substances which may be harmful They may be toxic fumes which people might breathe in and then they will be effected. Wearing protective gloves Wearing g a filter mask so that you don’t breathe in any bad fumes. Needle Need to be careful as you don’t know what substances they are yet so you may be allowing you to have an infectious disease such as HIV. You should use tweezers when picking them up and gloves See medical attention if you become exposed to needle. Alcohol and sweets on the floor It can be a tripping hazard where people who are at the crime scene could fall over. Look where you are going and wearing sensible shoes. Move and package them safely so no other accidents can occur but take a picture of them before.

Limiting cross contamination

Limiting cross contamination is very important in both crime scene and should be adapted the same way because during a crime scene because it can ruin evidence and stop a case as during court people like me will be questioned and asked how we collected the evidence. As a CSO my job is to prevent and limit the amount of cross contamination as this means something has come into contact with the crime scene after the crime has took place.

To limit cross contamination I wore protective personal equipment which is (PPS) this includes gloves, body suit, shoe covers, goggles and a filter mask may also be used to limit the amount of cross contamination e.g. no bodily fluids such as salvia, hair and fingerprints that may disrupt the scene. However for this crime scene not all equipment needed to be used as there was nothing that could cause of harm or disruption to the scene. If fibres or other substances get on things such as clothes when evidence is being collected, PPE is also worn to for health and safety reason to protect you against certain substances such as acid and poisonous gases. Everybody who enters the crime scene has to wear protective personal equipment because if they don’t it means the evidence in court will be questioned whether it is reliable or not and the criminal may get away with what they have done and innocent people may be at risk of getting convicted.

Correct recovery is very important within a crime scene as you have got to collect and recovery evidence in the correct way depending if the evidence is physical, chemical and biological. As the evidence may have to be collected via, casting, swabbing, taping, handpicking, shaking, brushing and vacuuming. All the evidence collected should be sealed with a evidence label saying ‘do not open’ as if it was to be opened there will be proof that it has been tampered with, a label also says the type of evidence, the date, time and names of who collected it for the proof of ID.

The first type of evidence that was collected was the white drug substance in a plastic bag which was chemical evidence this meant that the method of handpicking which is just using your hands. The packet was placed in an air tight plastic bag because before in can be tested in a lab to be a 100% accurate of what it is no one knew the harm it could cause if it was to reacted with anything or be in contact with skin. The evidence was sealed with an evidence label which says do not open.

The second type of evidence that was collected at the crime scene was physical evidence which was Paper document. The paper document was put in a plastic bag and was handpicked by using gloves this was because it was paper document so if it got wet while in the plastic bag then the evidence wouldn’t be destroyed.

The third type of evidence that was collected was biological as it was strands of hair. This means it was collected using tweezers and put in a porous bag so that nothing else can grow or get contaminated, a biological sticker was also stuck on.

The fourth type of evidence that was collected was a liquid substance but there were two types because in the two separate glasses the liquid was 2 different colours which suggest it could have been mixed with something else. It was collecting using handpicking with a pipette and putting the liquid into two separate vials.

Search Patterns

As a CSI I need to make sure the whole of the crime scene it searched properly in the correct way and not missing anything out, the different types of search patters is the inner spiral which is where you start at the perimeter of the crime scene and work towards the centre. The outer spiral which is where you start at the centre and work towards, parallel where a team of officers will work in a straight line and finally the grid which is two parallel searchers where they go in opposite lines.

For this type of crime scene which is a small room in a bungalow the type of search pattern that should be used is the inner spiral as this means no evidence can be missed as it is a small enclosed room using a search pattern. This would be parallel as it wouldn’t be useful as you can’t walk far in a certain direction and the more amounts of people you have in a crime scene the more chance of it becoming contaminated.

As I was searching the crime scene I took pictures from all 4 corners of the crime scene this is because when you go back to look at the photography evidence you may spot something that you didn’t find at the crime scene when you was there. It also gives you another perspective to look at as you may visual something in a different way that helps the case.