Introduction
Estimating the time in which a death occurred has become an important aspect of carrying out an investigation. Some deaths occur in mysterious circumstances that leave the family of the bereaved wondering how and when the death occurred. Even though they will have nothing to do to bring the dead back to life, they are usually curious to know how and when the death occurred. This will be necessary for ensuring that the bereaved family obtains justice and is also protected from similar occurrences. Knowing how and when an individual died will help hasten the grieving period as the family will release the individual to rest with full assurance of what happened. It has become mandatory for the criminal investigation department to establish the cause of any mysterious deaths. At times it may not matter where and when the death occurred but rather the truth is known not only by the family of the bereaved but also by the criminal investigation department. Knowing the cause of certain death will also assist the family and the community, in general, to know how to handle the deceased. Some people may die of mysterious illnesses which may be communicable (Cruz, 2000). Unless corrective measures are taken, the people around may succumb to the same unknowingly. The forensic study has become necessary in this procedure where certain mechanisms are used to determine when and how the death occurred.
Procedures used to estimate the time of death
Body temperature
One of the most reliable methods that are used to determine the time at which death occurred is the body temperature. Forensic studies have revealed that there is a rate at which the body cools immediately after the individual dies (Geberth, 2006). By looking at the current temperature when the individual has been identified to have passed on, they can be able to know the estimated time when he died. The rate at which the body temperature goes down is however determined by several factors which may include the clothing that they are wearing, the temperatures of the surrounding environment, the age of the individual, his or her body weight and their body fat. An adult will cool faster than an infant and a naked body will also cool at a faster rate compared to that which has coverings of a certain kind.
The environment in which a person died determines how faster they cool which is usually displayed by the growth of maggots on the body. A body in a warmer place will be more conducive for the growth of maggots compared to that which is in a cooler place. There may hence be a difference between the rates of decay of bodies that have died at the same time yet in different environments. Unless an appropriate estimation is carried out, it may seem that that which has been found in a warmer place died long before that which is in a cooler place. The loss of body heat which is also known as algor mortis is taken from the rectum. From such recordings, it may be easier to estimate the time when the individual died.
Rigor mortis
Rigor mortis refers to a condition of the body muscles stiffening immediately after death. Once a person loses his or her breath, the body tends to remain at a similar position that it was before it died. If they were holding something in a particular direction, the position of the hand will remain in that particular direction. The cause of their condition is usually the building up of waste materials as well as the failure of the process of enzyme reaction. The waste product that rises up when the body organs stop functioning in death is due to the high concentration of lactic acid. Continuous build-up of the lactic acid causes the body muscles to shorten and stiffen (Sonne 2006). The build-up of this acid first takes place on the jaw bones and other smaller muscles is hence the areas that will stiffen faster before the other areas of the limbs and the legs. Rigor mortis occurs between 12 to 24 hours of death and increases again within 36 to 48 hours. After forty-eight hours the body starts to decay and hence the stiffening process is minimized. Rigor mortis is an important element that is used by the criminal investigation department to determine the time in which the individual passed on. They will basically look at the muscles that have already stiffened from which they will know the time period of the death.
Lividity
Lividity is also referred to as liver mortis or hypostasis, this is basically the process by which blood drains to the lower body parts. This process is influenced by the gravitational pull on the ground. After the death of an individual, the body is not controlled by internal organs. The reaction of the body fluids will hence be influenced by external pressures such as gravity and temperature. The draining of the blood usually takes place within the first two hours after death; it usually takes an average of six to twelve hours before the process is complete. This is hence an important procedure that can be used to determine the time in which the death occurred. It can however not be used independently to determine the results. It is mainly helpful when used together with other signs and information that has been obtained on the death of an individual. The main reason why such lividity investigations may not be sufficient is that some areas of the body that are under pressure may not show them. If the body has slightly been moved from one place to another, lividity may not be seen. It may however be reliable if the body remained at a similar position that it was immediately after death.
In addition to lividity, the body coloration will also have a lot to say about the kind of death that the individual experienced. If a person died due to the poisoning of carbon monoxide, the skin will have a pinkish color while the one who died due to the poisoning of cyanide will have a bright red color. The occurrence of lividity may also be a good determinant in ascertaining the position of the body when the individual died. The discoloration of the skin will mainly take place in body areas that are not in contact with the ground or another body part. This basically means that if the body was moved from its position after lividity has taken place, the places that are colored will be a clear indication that they were exposed and not on the ground or a certain object. The investigation department will hence look for the discolored portions basically to find out the color of the body to know what the individual died of and the position that they were lying on.
Eyes
Eyes are also an important determinant of the time when the death occurred, the eyes being the most sensitive part of the body will show an abrupt change. The eyes will stop reacting to the changes in the external environment and generally remain at a standstill. The changes that take place in the parts of the eye are different which forms an important component of investigating the time in which the death occurred. The immediate occurrence is the loss of light reflexes and the cornea (Robb, 2001). The next thing that occurs is that the eyes will be fixed in a dilated position. There are also other investigations that can be carried out in the eyes that can determine how and who killed the individual. There are images that will be recorded in the eyes shortly before the individual died which can be screened to determine the events that happened before the individual passed on.
Cadaveric spasm
Cadaveric spasm is the process by which the hands stiffen immediately after death. This may be mostly revealed if the individual died while they were holding a certain object in the hand. This is a method that can also be used to determine the time in which an individual died. The stiffened body part may remain to be in such a position until decomposition occurs. As observed earlier the rate at which the body decomposes is determined by the surrounding temperatures and the place where an individual died. There is no time limit for cadaveric spasms and will mainly stop when the body begins to decompose. Depending on such environmental factors, the criminal investigation department will be able to determine the time in which the individual died. It will be ascertained to be recent if the body parts are still stiff. When the body has started to decompose it will be definite that the death occurred sometimes back.
Putrefaction
Putrefaction is a term used for the decomposition of the body. This forms an important element in determining the time that the death occurred. A body that has started to decompose means that it passed on some days ago. It is however determined by the environment that the individual died in and the kind of death that the individual experienced. Putrefaction is caused as a result of tissue breakdown which is caused due to the cessation of bacteria and enzyme reaction. It is a procedure that takes place in stages. In the first stage, the tissues dissolve into gases; the gases will then be transformed into liquids and thereafter into salts. These are the different stages that will be observed by investigation police to determine the possible time of the death.
Within 36 hours of death, a greenish color will be observed in the areas of the abdomen, neck and shoulders. There is also a certain kind of swelling that will be observed on the body mainly due to gasses that have been caused by the bacteria. There will also be stresses of blisters that are full of fluids on the skin of the body. Finger nails and the hairs on the body will fall off due to discontinued body activities. Some of the factors that may influence the rate of putrefaction include environmental temperature, body fat and humidity. The criminal investigation department will put all these factors into consideration to ensure a correct estimate is done. In considering environmental factors, it will have to be ascertained if there was any change in the surrounding temperature or whether it was constant. It may be a bit challenging to carry out investigations in an area whose temperatures have been changing.
Marbling
Marbling is another important feature that is used to estimate the death of an individual. During this process, there is always the hemolysis of blood vessels that reacts to the hemoglobin and hydrogen sulfide. This process usually leads to the development of certain discoloration that may be purple, red or greenish. The discoloration usually takes place along the blood vessels. In determining the time when an individual passed on, the color of the discoloration is usually observed. The color along the blood vessels will change as the individual stays longer. Using such color, the criminal investigation department will also be able to know the kind of death that the individual was exposed to. Any kind of poisoning will make the blood vessels adapt a color after the reaction of the chemicals with the blood.
External factors that may be used to ascertain the death of an individual
Apart from the observations that may be recorded on the body of an individual, there are other factors that can be used to determine the time in which an individual passed on. The external environment as discussed earlier influences the rate at which the body will decompose which is an important factor that is used by the criminal investigation personnel. Other factors that may be considered include the insect that grows on the individual, plants and vegetation around the body of the individual and the environmental condition. We will discuss each of them to find out how they help in criminal investigations.
Plants
The study of plants around the dead body can be facilitated by botanists. They have the ability to analyze the plants that have grown around the body to see how long the body has been lying. If the body was killed on plant vegetations, then they will exert pressure on them and hence changing their appearance. There are factors that are necessary for the general growth and sustenance of a plant. If the plants are put under a certain kind of pressure; it basically means that they are being denied access to important elements of their growth (Coyle, 2005). They will hence display features that will reveal that they either lacked air or sunshine necessary for chemical reactions. The color of the plants will be an important feature in such investigations. If they have only changed their color and not really decayed, the time will be investigated accordingly. There are also certain species of microscopic plants that will grow on the body of the individual that can be used to determine when they passed on.
Insects
Insects will always look for an environment that is at standstill to lay their eggs and probably feed their maggots. When they find a body that has been cold for sometime, they lay their eggs there with the hope that after hatching, the maggots will be able to feed on them. The entire process, from when an insect lays an egg and the same hatches into a mature insect will help in the investigation of the time of death. If the body is found without any maggot then, the investigations will prove that the death occurred sooner. Depending on the growth stage of the maggot, it will tell the officers for how long the dead body had been lying there. As the maggots mature into adult insects, they will also hatch eggs that will develop into maggots. A body that has been in a place for a long will hence have a bigger number of maggots and probably adult insects that will be feasting on the flesh. This is however determined by the external environment which may be conducive or not conducive for the maggots to grow. In extreme weather conditions, the maggots may not develop and hence die away (Miller, 2002). This is a procedure that will be helpful to the investigation officers when the death occurred in a warm environment. In studying the lifecycle of the insects, entomologists are able to observe the developmental stages of the insects and maggots found beneath the skin of the individual and hence be able to estimate the time when the death occurred.
Adipocere
Adipocere is a greasy substance that develops on the body surface especially if the death happened in a swampy or moist area. Adipocere is microscopic during the initial stages of development. However, at advanced stages, the liquid can be observed with naked eyes. Forensic investigators can be able to investigate the occurrence of this liquid on the skin of the body and examine it to know for how long the body has been at a particular location. The period that may be taken for the adipocere to be observed with the naked eyes is after three to four weeks. This, therefore, means that if they will have to see the liquid using a microscope, then the body has not stayed there for over two weeks. They may however not need to carry out much investigation if they can physically see the liquid substance.
Mummification
Mummification is a process through which the body solidifies and becomes stiff. This is a condition that mainly develops when there is a dry heat and when there are air currents. This is a process that will slow down the rate at which the body will decompose. A body that has been exposed to such a condition can be preserved for very many years. Even though such a process may take place naturally, it may be done intentionally by individuals for the main purpose of preserving it probably for further studies or investigations (Bass & Jefferson, 2004). Considering the length of time that such a body may take before decomposing, it may not be easy to determine when the death occurred. If the process occurred naturally, it will assist the officers in determining how and when it occurred and hence providing evidence for any other similar study. If the process was done probably by an individual that was involved in the murder of the victim, then they will be able to know their intentions which will still be necessary for the investigation process.
Other evidences
There may be other evidences apart from the ones mentioned above that can be utilized by the criminal investigation department to determine the time when the death occurs. This may be through various interrogations that may be carried out on the friends and family members. They may also identify other witnesses who may have been with the victims’ moments before they passed on (Leach, 2005). Other information may also be gathered through communication devises such as mobile phones and email conversation. The last people that the victim was with, or talked to, can facilitate the process of investigation. In identifying the possible witnesses to the murder or death case, the police can identify the fingerprints by intensively checking the body and surrounding environment of the dead. The process may however be interfered with by environmental factors especially if the body has been there for some time.
Conclusion
The procedures mentioned will be used at the same time to ensure that the police come up with exact results. Considering the many factors that may hinder the information gathered from being real, they are used interchangeably. There are some procedures that may not be relevant for a certain study and hence require the police to take the necessary measures. Any interference on the body by a third party may interfere with the results of the police. It is hence necessary that when a dead body has been discovered somewhere, it is reported immediately to the forensic investigation department to carry out the necessary tests. The tests will ensure that the affected family obtains justice by identifying and prosecuting the criminals. The investigations will also be necessary for protecting the entire community from similar occurrences.
Reference list
Bass, B., & Jefferson, J., (2004), Death’s Acre: Inside the Legendary Forensic Lab the Body Farm Where the Dead Do Tell Tales, London: Berkley Pub Group.
Coyle, H., (2005), Forensic botany: principles and applications to criminal casework, New York: CRC Press.
Cruz, A., (2000), Forensic entomology: estimating the time of death using insects in a Mediterranean environment, San Diego: National University.
Geberth, V., (2006), Practical homicide investigation: tactics, procedures, and forensic techniques, New York: CRC/Taylor & Francis.
Leach, M., (2005), Estimating time of death using forensic entomology: entomological field study, San Diego: National University.
Miller, R., (2002), The affects of clothing on human decomposition: implications for estimating time since death, Knoxville: University of Tennessee.
Robb, J., ( 2001), Betrayal in Death, London: Berkley Books.
Sonne, W., (2006), Criminal Investigation for the Professional Investigator, New York: CRC Press.