Basic Rules: For evidence to be legally accepted by the courts:
At the Scene: The recognition, identification and protection f evidence is very important. This may require complete notes, photographs, x-rays, rubber gloves, syringes, needles, forceps, scissors, knife, and proper containers adequately labeled and identified. Plastic vials and jars are useful for small samples, e.g. hair, bullets, blood and organs. Plastic bags are useful for organs, clothing and larger articles, and to cover the hands or other parts of the body. Larger plastic containers may be used for bodies.
At the autopsy:
To maintain chain of custody, evidence should be transmitted in the following form.
Case reference: | Date: |
Item: | Signature of holder |
(Bullet, Case reference: iscera,etc) | Signature od recipient |
Transferred to |
SAMPLES FOR DNA ANALYSIS
1. From body of the diseased.
The biological samples should be collected in following priority order in case of dead person.
a. Skeletal muscle (deep muscle) / Tissue – The concerned M. O. should collect the least decomposed portion of the tissue and it as soon as possible to avoid further decomposition.
b. Tough tissue – If the decomposition has already started collect the tougher tissue for which the decomposition rate is comparatively slow.
Following types of tissue are observed to have lesser degree of decomposition.
c. Tooth – Forward all the teeth present with the body.
d. Scalp hair with roots – Forward bunch of scalp hair with roots. Pluck the scalp hair don’t cut them with scissors.
e. P. M. Blood.
f. Bones – If the skeletonisation of the deceased is complete and no tissue or other options are available, then the longer bones of the body such as Femur should be forwarded. If some dried tissue or tendons are stuck up with the bones, then do not remove it, as there are some chances to get the DNA from it.
2. Crime scene and other Exhibits –
a. Blood stains – In murder, attempt to murder and other related cases, blood stained, clothes, scrapings, blood stained weapons and other related exhibits should be forwarded as per the requirement.
b. Semen stains – In rape cases, clothes of victim and accused, clothes at crime scene, condoms and other related exhibits should be forwarded.
Mode of parcel and proper preservatives for respective samples.
Sr. No. |
Sample |
Mode of parcel |
Preservative |
01 |
Tissue, Muscle piece scalp skin etc. |
Put the sample in clean, sterile plastic or glass container add the preservative as recommended. Bring the sample in ice. |
DMSO or Normal physiological saline or 4% EDTA solution or keep the tissue as it is in –20 0 C refrigerator. |
02 |
Blood |
Clean sterile glass vial for P.M. blood. For control blood samples, tubes are supplied by FSL. Bring the samples in ice. |
4 % EDTA |
03 |
Teeth |
Air dry all the teeth available, put them in dry, clean and sterile plastic or glass container and forward. |
No preservative |
04 |
Scalp hair |
Air dry the sample, put in dry, clean and sterile plastic or glass container and forward. |
No preservative |
05 |
Bone |
Air dry and wrap in clean brown paper. Do not macerate or treat with any chemical. If the tissue or tendon is stuck up to the bone, keep as it is, do not separate or disturb it. |
No preservative |
06 |
Blood stained clothes and scrapings |
Air dry the clothes and wrap in clean brown paper. Don’t pack clothes in wet or semi wet condition. In case of blood stains on the wall, scrap with a clean new razor blade. While scraping, take the precaution that paint on the wall does not mix with the blood. Put the scrapings on clean piece of paper and prepare the packet. |
No preservative |
07 |
Semen stains |
Air dry the clothes and wrap in clean brown paper. Do not pack clothes in wet condition. In case of used condom, reverse it carefully to bring its inside out, empty it’s contents on a clean dry & sterile piece of cloth. Dry the cloth and forward. Also dry the condom pack in a brown paper and forward. |
No preservative |
At scene call police and work in cooperation with them.
He can proceed with investigation along following lines
After measurements and the photographs are made and the finger prints taken, the weapon, if found at the scene, shall be taken into custody and placed cordially in a container. Other materials and evidential values such as hair, nails and objects, clothing on which there are stains should be collected in sample quantity and retained in transparent plastic bags. In a case of suspected poisoning. The bottles, boxes, vomit and even fecal matter of the scene should be all- labeled chain of custody maintained.
If death due to natural retain blood and urine samples-poisoning.