at the crime scene
Once officials arrive at the scene of a crime, the first and foremost priority of a police officer is to assist or preserve the life of the victim (if one is present), making sure that he/she is not exposed to any danger. The officer does however, have to ensure that his/her own safety is not endangered during this process. They are then to alert senior investigating officers, reporting on the situation of the crime scene and subsequently notify ambulances and the fire department if necessary. The time of arrival on the scene must essentially be noted down as well as all other significant observations. Whilst doing all this, the officer must take care not to touch or move anything.
Making sure evidence does not get cross-contaminated in any way, either at the scene or whilst it is being examined at the laboratory (lab) it is critical in investigations. Investigators and all professionals at the scene must wear gloves to avoid getting their own prints on items. Each piece of evidence is photographed, collected, numbered and put into bags.
Making sure evidence does not get cross-contaminated in any way, either at the scene or whilst it is being examined at the laboratory (lab) it is critical in investigations. Investigators and all professionals at the scene must wear gloves to avoid getting their own prints on items. Each piece of evidence is photographed, collected, numbered and put into bags.
sealing the scene
Sealing the crime scene is essential to protect any evidence it contains, the more people that visit the crime scene, the more difficult it becomes for investigators. Not only does sealing the scene preserve important evidence, but it also helps in the identification of potential suspects/witnesses by eliminating the possibility of these people leaving/entering before officials have the scene fully detailed. The section that has to be sealed depends on the individual crime and the crime environment, but the sealed off area should be big enough to enclose not only the immediate area of the crime, but also the points of possible entry and exit.The section then becomes accessible only to the relevant personnel involved with the case. This method makes it much easier to manage the crime scene, as it provides a protected zone for incident vehicles and also for dealing with the media.
To prevent evidence contamination, personnel numbers are kept to a minimum at the scene of the crime and only one entry and exit access point is established to be utilised by all forensic and scene investigators. A log of everyone who visits the scene is kept, including arrival and departure times and any evidence shifted/taken from its original place. This is to ensure that evidence tampering does not become an issue while in court.
To prevent evidence contamination, personnel numbers are kept to a minimum at the scene of the crime and only one entry and exit access point is established to be utilised by all forensic and scene investigators. A log of everyone who visits the scene is kept, including arrival and departure times and any evidence shifted/taken from its original place. This is to ensure that evidence tampering does not become an issue while in court.
EVIDENCE
Evidence is the most important factor in determining a just verdict in a court of law. The various tests used to decide the truth from an item of evidence range from the analysis of bloodstains to trace evidence.
Without it, jury members may doubt what the police and forensic specialists have found and the criminal could be set free.
Forensic laboratories all follow the same basic rules and regulations. Any item of evidence that enters the lab must never come into contact with anything that could contaminate it. Its progression through each of the lab's departments must be fully recorded. Once the sample is in the lab, the most simplest test is always carried out first i.e to verify that the item is really what it is, before moving onto more expensive, but precise procedures to discover the evidence the item might hold. Any tests that may destroy the piece of evidence are carried out last, once all other tests have been completed.
In most labs, a unit commonly known as a 'trace evidence unit' forms an area where scientists look for clues in evidence such as hair, fabric, dust, fibre and skeletal remains.
Without it, jury members may doubt what the police and forensic specialists have found and the criminal could be set free.
Forensic laboratories all follow the same basic rules and regulations. Any item of evidence that enters the lab must never come into contact with anything that could contaminate it. Its progression through each of the lab's departments must be fully recorded. Once the sample is in the lab, the most simplest test is always carried out first i.e to verify that the item is really what it is, before moving onto more expensive, but precise procedures to discover the evidence the item might hold. Any tests that may destroy the piece of evidence are carried out last, once all other tests have been completed.
In most labs, a unit commonly known as a 'trace evidence unit' forms an area where scientists look for clues in evidence such as hair, fabric, dust, fibre and skeletal remains.
PHOTOGRAPHY
The use of photography is perhaps the investigators most useful tool at the crime scene. With digital cameras it is easy to take a shot of everything and anything that is at the scene. Camera forensic photographers record anything that needs to b disturbed before it is moved or removed for reference.
However it is not always easy, sophisticated equipment and lighting techniques are often necessary to show clues that are invisible to the naked eye. Cameras are also used to photograph large items that are too big to be moved to the lab.
However it is not always easy, sophisticated equipment and lighting techniques are often necessary to show clues that are invisible to the naked eye. Cameras are also used to photograph large items that are too big to be moved to the lab.
WITNESSES
Potential witnesses are detained and removed from the scene by police officers to be searched and questioned. Their condition, statements and behaviour are all documented for further analysis later into the investigation.
The police must also ensure that suspects are not allowed to return to the scene of the crime before it has been fully documented, in order to prevent 'evidence tampering'. This procedure is put in place to prevent the witnesses discussing what they each saw and prevents one's recollections of the incident being influenced by the ideas of another.
The police must also ensure that suspects are not allowed to return to the scene of the crime before it has been fully documented, in order to prevent 'evidence tampering'. This procedure is put in place to prevent the witnesses discussing what they each saw and prevents one's recollections of the incident being influenced by the ideas of another.
WITNESSES CAN BECOME SUSPECTS
No matter how careful forensic scientists and officers are, witnesses are able to shine a light on a crime and give vital information about the identity of a criminal.
Witnesses can also become suspects in a criminal investigation.
Suspects may be held at the police station for a certain period of time (varying for each state) during which the scene is analysed and sealed off. At the same time witnesses at the scene are detained and separated from one another up until they have given statements and it is then at this point, witnesses may be free to go.
Witnesses can also become suspects in a criminal investigation.
Suspects may be held at the police station for a certain period of time (varying for each state) during which the scene is analysed and sealed off. At the same time witnesses at the scene are detained and separated from one another up until they have given statements and it is then at this point, witnesses may be free to go.