Analysis of Skeletal Remains in Criminal Investigation

Many buried bodies come to light accidentally. Occasionally, information is received that a body is buried at a particular location.

Excavation/Exhumation

The act of placing a person or object into the ground is called Burial or interment or Inhumation. Exhumation means digging out something which has been buried, especially corpse. The word Exhumation derives from Latin words ‘ex’ meaning ‘out of’ and ‘humus’ meaning ‘soil’. Thus in simplest form the word exhumation means ‘out of soil’.

Exhumation is generally considered sacrilege or taboo in our society. It is the norms of most of the cultures that the dead should not be disturbed. Despite all cultural and religious barriers, exhumation is carried out throughout the world.

Exhumation plays vital role in criminal investigations. It helps to catch the culprits in many mysterious murder cases.

Role of Police Officer During Exhumation

The police officer responsible to investigate such a case is required to carry out following major tasks at the scene:

To protect the scene of crime
Record the undisturbed scene of crime
To excavate/exhume the dead body
To record the scene at every stage of excavation
To conduct inquest
To collect the skeletal remains
To collect other physical evidence including soil samples from the buried area
To seal the skeletal remains to forward it first for post-mortem examination and secondly to the Forensic Science Laboratory for other examinations.

The I.O., soon after excavation of the skeleton remains, place the bones in anatomical position to find out age, sex, stature, race, anatomical deformities, cause of death, time since death and manner of death.

He should also try to find out the missing bones possibly eaten or taken away by animals in case skeletal remains are found in forest areas.

Who authorizes exhumation?

In India, Exhumation is to be carried out under the written order of the First Class Magistrate (judicial or executive) empowered by section 176 Cr.PC. Police are not vested with power to order Exhumation.

As per section 176 sub-section (3) of Criminal Procedure Code, 1973 :- Whenever such Magistrate ( Magistrate who is empowered under section 174 Cr.PC. & 176 Cr.PC. ) considers it is expedient to make an examination of the dead body of any person who has been already interred, in order to discover the cause of his death, the Magistrate may cause the body to be disinterred and examined.

In India, police CAN NOT order exhumation. In India it is a usual practice for magistrates to constitute a board comprising of three different forensic pathologists from three different medical institutions.

The board jointly supervises exhumations and conducts postmortem examination of remains. Although law does not specifically require the formation of such a board, it is usually done in order to send out a message to the aggrieved relatives that the postmortem was done in a free and fair manner with no pressure from any quarters, and also that no inadvertent mistakes could be made (which could perhaps be there if there were only a single doctor).

Time limit for exhumation

In India, there is no time limit for ordering of the exhumation, but many western countries have well-defined time limit up to which exhumation can be done. For instance, in England there is no time limit, France has the time limit is 10 years, and in Germany 30 years.

Some Steps that is followed during Exhumation

The outermost surface of the place should be observed carefully, photographed and then cleaned properly of extraneous materials so that the actual dimension of the place is visible which should be measured, sketch should be drawn.
Take a note of the vegetation of the site.
A stainless steel pointed end rod of 4-5 feet length and about an in diameter is highly suitable for the purpose of probing.
Soil or any surface should be dug slowly, layer by layer carefully so that no part of the human remains is lost or broken in the process.
All the bones, recovered should be collected at one place, preferably in an open container.
The soil of each of the layer should be sieved to recover pieces of human remains and other evidences such as the weapon of offence, hair bloodstains, clothes and any other material used in the commission of the crime.
Doctor should preferably be called to the scene to examine the bone and help the police to estimate the time since death, species, age, sex, cause of death and other aspects relating to the establishment of the identity of the deceased.
In the absence of a doctor, the I.O. may have to arrange all the bones in anatomical position and try to find-out the cause of death and other details such as species origin, age, sex and try to establish the identity and conduct the inquest.
The long bones should be individually measured and recorded.
Bones after arranging in anatomical position should be thoroughly measured.
Bones should be packed in a box taking care that no damage is caused or any part is stolen during the transportation to the Forensic Science Laboratory. Above-mentioned procedure for packing should be followed.
Collect the insect larvae in 10% Formalin in a bottle and seal. The insect larvae at different stages of development provide important information about the time since death. Forensic Entomologist working in Biology Division of the Forensic Science Laboratory examines the maggots and gives his report.
Samples of soil from the adjacent areas should also be collected, packed separately and sent for matching with the soil adhering to the bone.
Bones and other articles recovered should not be cleaned or washed.
In advanced countries, sophisticated equipment such as temperature sensing probes or radars are used to locate the body as much as 4-5 feet below the surface.

Examination of Skeletal Remains

The basic job and responsibility of the Forensic Biologist are to provide information leading to the identity of the person, cause of death and also time since death.

Determination of Age: It is possible to give an opinion about the age of person from the bones. If the entire skull is available the task of scientist becomes easier as eruption of tooth, fusion of skull sutures are important characteristics based on which opinion on the age can be given with high degree of certainty. The lower jaw (Mandible) alone can give enough indication about the age. Study of ossification centres and fusion process of long bones is indicator of age. Changes caused by osteoporosis and other old age changes on the bones give good indication of age for the aged persons.

Determination of Sex: Determination of sex is another important job of the forensic biologists. Sexual dimorphism is evident in almost all the bones of human beings such as skull, long bones, pelvis, etc. Forensic Biologist can give opinion on sex accurately. Through morphological examination, it is possible to determine whether the bones are from human beings or animals.

Determination of Race: The scientists can give opinion on race by measuring cephalic index from the skull bone.

Determination of Cause and Manner of Death: In order to give opinion regarding the cause and manner of death,the forensic biologist critically observes each bone its pieces and fragments to find out mark of injuries, which could have caused death. Often in homicide cases, examination of skull reveals variety of fracture patterns including bullet holes, which contributes significantly to draw opinion about the cause of death. Besides, in violent crimes fracture of pelvic and long bones are also seen during examination. In cases of suspected poisoning, sample of bones are subjected to chemical analysis to detect poisons.

Determination of Time Since Death: By examining bones and the tissues combined with the insect larvae (Maggots), it is possible to provide opinion regarding the time since death. Of course, estimation of time cannot be very accurate as it depends on climatic conditions; nature of death (Death due to burn) and the manner and place the body was disposed.

Facial Reconstruction: Forensic Biologist can successfully reconstruct the face from the skull using Photographic or Vediographic Superimposition Techniques provided the investigating officer supplies recent photograph of the deceased. Forensic Scientists using modern techniques can reconstruct the face of a person with available pieces of skull unless the pieces are too small to piece together.

Skeletal Remains and Serological Examinations: If the sample available is too small to conduct morphological examination, in that situation the pieces of bones are subjected to serological examinations to determine the species origin, blood group substances etc. At present, DNA profiling can be successfully done from bone marrow and pieces of bones that can establish absolute identity of the person.