physical evidence


Each crime scene is different, consistent with the physical nature of the scene and  therefore the crime. Consequently,  the location of the physical evidence, will also be very different. The look for physical evidence at a crime  offense scene must, therefore be thorough and systematic. Where to search and what to search for will be depend upon the circumstances of the crime. The investigator,  who  is thorough  in his training and experience, will not find much difficulty in locating the evidence. What is required of him is an inquiring mind and a searching eye.


Physical evidence may be collected only after the initial search, photography and sketching of the crime scene. If it is a crime  of violence resulting in death and comitted indoors then all obvious evidential material on or near the body is collected before the body is removed for autopsy. The weapon of offence and any other type of  evidence left as a result of contact between the victim and assailant like blood, flesh etc. should be located.

If it is burglary, then the point of entry should be established and evidence of tool marks, tols etc. shouuld be looked for. Obvious items of microscopic evidences such as hairs, glass fragments, metal pieces , or other small visible items should be picked carefully wiyh forceps. After manual search is done, a vaccum sweeper equipped with suction attachment may be used, and the evidence, is missed can be collected. Search for fingerprints can then be made on doorknobs, glass panels, door leaf etc.

If the crime is comitted in an automobile, then glass sweepings of the upholstery and floors, fingerprints, blood, semen, hairs,  and fibers sgould be searched and collected.

Physical evidences collected from the scene of crime has to be handled, packed and preserved during a way that prevents any happening between the times it’s removed from the crime scene to the times it is receieved by the labortary. Change can  happen thanks to contamination, breakage, loss through improper or careless packing.

For collecting the evidence, packing material and tools ready to encounter any type of situation should be kept handy. Investigators are often provided with crim scene evidence collecting kits, containing most of  the things, which the investigating officers may need.


The examination of evidence whether it is soil, glass blood, paints, fibers etc. often requires comparison with a known standard or a conntrol sample. Therefore, while collecting physial evidenc, the investigator must not forget to collect the control sample. ‘control sample’ means sepcimen of materials e.g. smple of blood, vegitation or soil from the scene, hair from the victim which are collected for comparison with any questioned material from the crime scene. Control sample is essential requirement for all examination in the labortaory.

It should be remembered that ‘ likes can be compared with like’. In the same manner blood stain found on garments, soils or other substrate will require  unstained sample in rule out the false positive test on account of substrate interference.


Evidence collected at the sccene of crime can be so varied in type, size, delicacy, and degree of perishability that there can be no set procedure laid down to cover all asoects. Howver, each article  should bearing in mind the following points:

  1. Avoid temptation of picking up an article immediately on arriving at the crime scene.
  2. Use pair of rubber gloves while handling every article.
  3. Handle article as little as possible so that no clue is lost or damaged.
  4. Prevent careless destruction of any evidence.
  5. Maintain integrity of the evidence material i.e. original character of the evidence.
  6. Ensure the chain of custody of evidence collected.

While handling evidence only such parts of the articles should be touched as are not likely to have been touched by anyone else previously as noted below:

  • In case of a flat object like a piece of wood or glass sheet only the edges should be handled.
  • In the case of tumbler, bottle only the rim and the bottom should be touched, using a single finger at top and bottom.
  • In the case of dagger or knife, the tips of the handle and the blade should be handled by the tips of the index fingers.
  • Firearms can be lifted with the tips of the fingers held against the ends of the barrels and the butt.
  • A fired projectile should only be lifted with a rubber tipped forceps.
  • Paper, hair, small pieces of glass or any small sized objects should be lifted with forceps.
  • Explosives and bombs should not be touched or handled unless one is sure that there will be no explosion by simple handling.
  • Blood, semen, liquids, chemicals, vomit and excreta etc, should be collected with the help of a spoon.


The following points should be borne in mind with regards to the packaging of the evidences:

  1. The exhibits contained in the packages not destroyed by knocking against each other and are properly added with cotton, thermocol etc.
  2. Each article should be separately packed and labeled so that the individuality and the identity are maintained.
  3. The packaging should be secure and nothing should penetrate or seep through, to contaminate the content.
  4. As far as possible all packets belonging to one case should be enclosed in a box or outer covering to form a parcel, unless disparities in size off various articles make this impossible. Packets of articles belonging to different cases shouldn’t be enclosed in one parcel.
  5. The exhibits inside the packaging, especially fingerprints articles do not come in contact with each other or the sides of the packages.
  6. The exhibits are not contaminated by being packed in unclean containers.
  7. The exhibits do not spill due to the use of unsuitable lids and stoppers.
  8. The container is strong enough to avoid damage in transit.
  9. The evidences are packed in a manner that they cannot be damaged when being unpacked.
  10. The labels are not pasted over weapons, tools or clothing’s suspected to contain any stains.
  11.  The labels should be numbered and should bear the signature of the forwarding officer and the number and the date of his letter of advice to the expert concerned.
  12. The topside of the box is always indicated on the top of the box containing the exhibits and marked ‘handle with care’.
  13. The exhibits are sent through a special messenger as far as possible. If sent by the post the parcel should be properly addressed, labeled, and preferably insured.
  14. Postal regulations should be kept in mind while dispatching exhibits like firearms and explosives.


All parcels should be carefully sealed by the dispatching officers and packed in such a manner that they cannot be opened without destroying the seals. All knots should be sealed. The seal should be  legible or clear. The seal should be kept in safe custody of the dispatching officers at all times. The seal might be private or official but should never be an impact of keys, coins, buttons etc. The facsimile of the seal should be sent alongside with the forwarding letter.


A letter of advice should be separately forwarded to the expert concerned, through a registered post or a special messenger in a sealed cover. A copy of this forwarding letter should be invariably enclosed in the parcel so that the link of the exhibits with the relevant case is maintained. The forwarding letter should contain the subsequent particulars:

  1. Name of the police station, district, State.
  2. Crimes register number and section of law.
  3. Brief facts of the case to include place and circumstances   of the seizure.
  4. Description of the articles in each packet.
  5. Nature of the examination required.
  6. Forwarding note of the officer through whom the articles are forwarded.
  7. Name of the investigating officer.
  8. Facsimile of the seals used on the parcel.
  9. Identification particulars of  the messenger carrying the parcel, and
  10. Certificate of authority to examine the evidence.


The term ‘chain of evidence’ means maintaining a record of  every article of  evidence, from the point of discovery at a  crime scene t its collection and transport to the laboratory of examination, and its temporary storage till it is finally submitted to the court.

The establishment of chain of evidence is necessary whenever evidence is presented in court as an exhibit. Otherwise, the evidence could also be inadmissible in court. For this there must be a systematic record of the names of the persons through whom the exhibits were passed and to whom they were delivered, their initials, time and date of receipt and delivery.

Each person in the chain of custody is responsible for the care, safekeeping, and preservation of an item of evidence while it is under his control.

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