Criminal investigators have a number of duties that extend far beyond what is so often presented on TV. The glory that surrounds detectives usually seems to showcase them in a way that makes them seem to be completely independent and higher ranked than standard police officers, however in reality detectives and street police often have similar duties. One duty that is unique to detectives, and more specifically, crime scene investigators, is the direction of crime scene investigation, including the capture of evidence.
CSI agents are in charge of direction of a crime scene’s evidence processing, as well as ensuring that two conflicting concerns are fulfilled; that the crime scene is preserved in as close to original condition as possible, and that the public is protected from the evidence. For example, it is important that the crime scene is left untouched for the sake of the investigation, but it is also unreasonable to leave a body in the middle of an intersection, in most instances; one of many considerations that must be evaluated at any crime scene.
With this in mind, I will now examine the many steps that must be taken when searching crime scenes and dealing with evidence; one of only many duties that criminal investigators have. There are a few things that need to be considered when investigating a crime scene; the first being whether it is requires a hot or cold search; that is, the type of search that is necessary given whether the suspect is assumed to still be on the scene. If the suspect is still on the scene, there will be a high risk investigation, where weapons are drawn and the search is complete as soon as the crime scene is discovered.
A cold search on the other hand involves a crime scene where the suspect is no longer on the premises, and thus the intensity is much lower. This search may continue hours or days past when the scene is discovered in order to further understand the circumstances, and may go beyond the scene and include interviews of local residents or other possible witnesses (co. wise. tx. us). As mentioned before, it is important that there is strong leadership in any crime scene investigation.
A team leader is responsible for the delegation of responsibilities to others, as without a strong leader the group would be considerably less effective in the investigation, not to mention the possibility for error that could result in a less-than-thorough operation. Beyond the individuals who are responsible with the investigation efforts, there are other members of a crime scene investigation team who are essential in a successful investigatory effort. For example, sketch preparers are crucial in recording an accurate depiction of the crime scene so that evidence can continue to be uncovered beyond the period of initial discovery.
If the crime scene were permanently gone following the conclusion of the clean up, the investigation could easily be halted for a lack of certainty over the crime scene; for this reason, the importance of sketch preparers cannot be undermined. Similar to the sketch preparer is the evidence recorder; this person is responsible for collecting evidence by placing numbered cards on each piece of evidence which would correlate with a log to show what each number represents (co. wise. tx. us).
Both of these jobs are essential in recreating a crime scene that can be used for evidence beyond the initial incident, as long as they follow proper procedure in handling evidence (such as using gloves, creating a easily identifiable and correct key in the log, and ensuring that a sufficient number of photographs are taken before anything is physically moved) in order to recreate the situation in the most realistic way possible, These are only two of the many important figures and customs in a crime scene investigation, but are no less important in the nvestigation than the first detective to arrive on scene or the last to leave.
While the persons working the scene of a crime are essential to the investigation, there are a number of codes which must be followed in order to ensure that the scene is properly investigated. To begin, there are a number of different methods for searching the crime scene which can be utilized. The first is specific to indoor crime scenes, and is called an Elevation Zone Search (co. wise. tx. us).
These searches involve searching specific parts of the room(s) based on designated heights; for example, one might be restricted to searching only floor to waist height, while someone else is searching the area between their waist and chin. This allows people to focus on specific regions; a technique which is meant to reduce the likelihood of overlooking a given section. Another technique used for indoor crime scenes is the Overlapping Zone Search (Co. wise. tx. us), eader watches the investigation of their time as they scour the room for any possible clues.
In this method, people are able to double check what others have already examined, which again, is intended to reduce the chance of missing anything important. Furthermore, there are a number of methods for the physical movements across a crime scene, each of which has its advantage in assisting investigators in clue recovery. These include strip searches, spiral searches, and grid searches (co. wise. tx. us), each of which may vary depending on the circumstances at the scene.
Once the crime scene has been completely and thoroughly investigated and evidence has been recovered, the next and equally important step is the collection and preservation of the evidence. The ease of contaminating evidence means that the collection duties are extremely important, not only for the safety of those running the search (explosives, bodily fluids could certainly impact someone negatively if not properly handled), but also for the sake of the investigation. Improper storage can lead to faulty or inconclusive evidence, neither of which bodes well for the success of the investigation.
According to George Schiro, a forensic scientist for the Lousiana State Police Crime Laboratory, generally the most fragile evidence will be collected first, as this is the most likely to be damaged and therefore rendered useless. In some cases, precedent in collection will be given to items which are in need of being moved; guns, knives, bodies and so on; items which are a potential harm or disruption to the public. Schiro states that the most commonly used vessels for evidence collection are packets, envelopes, and bags; unbreakable containers and cans are used for liquids and arsonrelated evidence.
There are time restrictions on evidence collection, especially when the collected evidence is wet; the golden rule is that two hours is as long as evidence can be stored in a plastic container; exceeding this time opens the evidence up to contamination. Schiro continues to note that there are different methods for collection depending on what type of evidence has been found. Fingerprints are crucial in confirming an individual’s presence at an event, so it is extremely important that these are properly lifted and stored for examination at the crime lab.
Powders are used to bring out the fingerprints either for lifting for photographing, depending on the ability to succinctly lift them. Blood is also extremely important in crime solving, and therefore necessitates extreme caution when transporting it from the scene to the lab. If blood has stained an easily movable object, shipping the item to the lab via a paper bag is the most common method. If the stain is on a less-movable object, the stain can be transcribed onto a thread or other absorbent material, dried, and then packaged in one of several containers.
The entire stained object is not necessary for the investigation, as the biological qualities of the substance do not change with the addition of water for transcription just as the shape of the stain is not important for the correlation of blood and criminal. While some collection methods seem obvious, such as carefully placing a gun in a designated container while avoiding unnecessary fingerprinting, other evidence may be less easy to capture for analysis. Tire tracks and shoeprints, for example, are not so easily transported.
Skilled photographers are absolutely necessary in capturing such evidence; angle of flash, lens, and various other factors are essential when it comes to recreating the evidence in the lab. Sometimes it is possible to lift shoeprints in a similar fashion to fingerprints, but photography is always welcome and can do nothing but add to the legitimacy of the evidence (Schiro). Sexual assault cases can have different difficulties not experienced in assault or murder crime scenes, as the (usually) living person is quickly processing the evidence beyond use due to regular bodily functions.
Due to this consideration, it is especially important to recognize that time is of the essence when attempting to attain samples of bodily fluids which may be able to be presented as evidence. When a crime is committed there is always, at least to some degree, a crime scene which can be used for evidence. Whether this is a murder, assault, sexual assault, or robbery, even the most skilled criminals are usually unable to clear the scene of all evidence. With this in mind, it is extremely important to have highly educated and experience crime scene investigators on the scene as soon as possible.
The various jobs which compose this team work in harmony with each other if constructed properly, and it would be difficult to complete the job without contributions from each segment of the team. While there are outlines of how to complete a search and record evidence, discretion must be used from time to time with the understanding that not all crime scenes are the same, and the variable circumstances may cause a situation which does not lend itself well to being completed by the book”.
For this reason it is important to understand the basics of crime scene investigation while recognizing the importance of innovative and derivative thinking. Crimes are much more likely to be solved when a combination of discretion and rule-following are utilized, and a successful police unit and crime scene investigation team are likely to have the means to accomplish their goals; a responsibility which ultimately comes down to their goal of meeting the needs of their customers.