There are many series of tests that are being conducted in order to identify the properties of a white powder and to specifically determine if such is an illegal drug such as cocaine or ecstasy. Not only that, such tests can also determine the exact amount of the properties that can be found in the white powder. One of the quickest tests that chemists and forensics are using is the Thin Layer Chromatography or the TLC. With the use of a TLC plate, the white powder mixture or a small amount of it will be placed near the bottom of the TLC plate. After which, the plate will be placed on top of a solvent to wet the bottom of the plate. As surely as the solvent rises to up to the spot each component of the white powder will have its equilibrium established accordingly together with the determination of the various components of the white powder. After such test is completed, another step of visualizing the plates will be completed. Using a UV lamp, the white powder will now be determined if it contains cocaine or not (Vogel, 1996).
The third test that is being used by forensics in determining and identifying white powder is the infrared spectroscopy. A small amount of the white powder is placed in the surface or the platform of the device. Then the device will record the analysis of the sample and will immediately identify if the sample contains a mixture of cocaine. Finally, in order to determine the amount of cocaine substance in the white powder mixture chemists use the liquid-liquid extraction method as part of the series of tests. During this test, there will be a partition between the components of the white powder sample. It separates the compounds found on the given sample. Apparently, the sample powder will be separated into two liquids which are immiscible in nature. It will form water and the other liquid known as organic solvent. By doing so, the forensics will easily determine the chemical reactions that establish the components of sample.
Proper Collection and Preservation of Paint Evidence
Forensics has revealed that in all hit-and-run cases, paint evidence can easily be found.
Such evidence can be used in order to help the victim be linked into the perpetrator of the crime. In the process of collecting paint evidence, it is important to note that pedestrian victims of hit-and-run will surely have paint transferred into their clothing. However, in most cases, the paint evidence is only visible using the microscope since the quantities of the paint evidence are microscopic in nature. In such cases, it is very crucial to collect the garment worn by the pedestrian victim. It is in this process that the garment, if found wet, must be kept dry. However, it must not be handled so much so excessively in order to preserve the garment. After the paint evidence has been collected, it should be preserved in such a way that the garment must be wrapped in rolling paper or paper bags to be delivered to the laboratory that will conduct further study and investigation. If there is more than one garment, such must be placed separately in a rolling paper or plastic bag.
It is likewise important for the investigators to mark the area of the garment where paint evidence is spotted. This is to minimize time and the factors to which the laboratory will conduct a research and further study. The collection and the preservation of the paint evidence must be made with applying a lot of caution because of the fact that most of the hit-and-run cases are not solved because of its complexity. In a crime scene, all paint evidence must be collected and preserved even those that can be found on the floor and the surroundings. The investigator must not be focused alone on the garments worn by the pedestrian victims. Other factors such as flakes on the floor must be given consideration. This is because of the fact that since paint of various cars maybe the same. The determination of which automobile perpetrated the crime is hard to be known since many cars are the same.
Proper Collection and Preservation of Fire Evidence
In cases of arson and any other crimes or situations where a fire broke out, investigators search for fluids that are flammable in nature in order to collect evidence that can be subjected to examination and will eventually determine the cause of the fire.
In the manner of collecting fire evidence, it is important that the investigators must not be confined only to the doors or window that have been burned and affected by fire but rather extend to the materials and areas where traces of burning are not apparent or where ignition cause by fire had failed. This is merely to ensure that all aspects and phases of the fire have been investigated enough to acquire strong and solid foundation of crime conclusion. In collecting material evidence of the fire, cans, rugs, wallboard, mattresses, upholstery and other materials must be searched and investigated. These materials may contain the flammable liquid used. In such a case that a gasoline has been used to instigate the fire, the odor of the substance can be used to solidify the conclusion that indeed gasoline was used. The material evidence may still have in it the odor of the gas. Materials with the smell of a gasoline must be collected in the area where fire broke out. If there have been amount of volatile liquids found in the area, it must be put into a glass vial which is clean and be sealed to avoid leakage and loss. It must be noted that rubber lined lid or containers that are plastic must not be used at all. Plain glass vial is recommended (Meloan, 1998).
Garments, soil, paper, and wood should be placed in metal cans immediately to avoid evaporation that will enable loss of the valuable components of the evidence found. The materials to be delivered in the laboratory must not be marked with anything. In marking the exhibit, it is the cans or the plastics to which the evidence were placed that should be marked. This is to avoid any alteration of the fire evidence that have been collected and preserved for laboratory tests and examinations.
Compare Fiber and Hair Evidence
Crimes are completed when there is a victim and a suspect. In the commission of a crime it is being assured that both the victim and the suspect have a direct contact with each other. During such situation, it is undeniable that microscopic materials and evidence are also transferred because of such contact. Such microscopic materials and evidence can be comprised of hairs and fibers. Fibers, on the other hand, can be characterized with vegetable, animal hair, synthetic or even mineral. With the usage of hair as evidence to a crime, it can help the forensics and the investigator to determine the race and the characteristic of the perpetrator. For example, in a murder case, hair that can be found in the crime scene which does not belong to the victim may help determine of the suspect has a curly hair or straight hair, if the suspect is blonde or not; or if the hair is synthetic or real. Hence, the process of elimination on the possible suspects can be adduced. The manner in which the hair was removed can also be traced. For example, the hair found in the hands of the victim may help in achieving the conclusion that the victim fought with the suspect. However, hair evidence is not as strong as the fabric materials that can be found in the crime scene. In addition, the forensic investigation will likewise determine the origin of the hair strands that have been found. They will determine if the hair is from the head, armpit or if it is pubic hair. This will help the court to know the necessary further actions and mode of investigation that must be conducted accordingly.
In court cases, fibers have strongly been used to convict a criminal. In one case, a fiber of a carpet that has been found in the crime scene and in the car, home and other murder victims have convicted a criminal. Fiber can easily be adduced as evidence as compared to hair that needs to undergo a process of DNA testing in order to prove that the hair found in the crime scene is really the hair of the suspect.
Unlike fibers, the materials that can be found in possession of the suspect and that which have been found in the crime scene is enough proof that the suspects must be held in trial to prove guilt or innocence to the crime that has just been committed and found. Hence, for a speedy disposition of cases, fiber evidence is more reliable as compared to hair that needs to undergo DNA testing first. The color and the components of the fibers are likewise being considered by the forensic investigators in order to ensure that right deduction of the crime scene is achieved.
When an arson or a fire has broke out in a particular area, the investigators will immediately conduct a collection and preservation of the fire debris that can be used as evidence and to be used as a material that will help establish the deduction of what flammable liquid has been used to rise a fire especially those flammable liquid that are odorless and needs to undergo testing for determination. When all the fire debris evidence has already been collected and preserved, the samples will be sent to the laboratories. The forensics will then used different procedures that aim not just to know the cause of the fire but to actually identify and determine accelerants. The headspace technique is normally being used. In this procedure, the samples are placed in a can that has a small lid at the bottom for heating purposes. When the can is already heated, the residue that is present in the samples will be trapped in an enclosed space in the container being used. When there is enough vapors needed to testing, the vapor will be collected with a syringe and placed in a gas chromatography. The gas chromatography is being used by many forensic laboratories since it has the capacity to determine the type and the name of the flammable liquid that has been used to start a fire. It has the capacity and the ability to know is the flammable liquid is kerosene, gasoline, diesel or any other kind. With this, it cannot be denied that arson can be solved through proper collection, preservation and analysis of debris.