How to take fingerprints of a dead body
Fingerprints are an infallible means of positive identification
as well as the easiest form of identification. Fingerprinting and its history are
very ancient. It is referred as most valuable evidence in criminal proceedings/
investigation. When a body may go unidentified due to death, then we use
fingerprints for identification of unknown dead bodies but there are some
challenges in taking fingerprints from Dead Body. Fingerprints recording of a
dead body are not as easy as in case of a live person.
Common Challenges are-
Stiffened fingers due to rigor mortis
Shrunken skin
Decomposition and Putrefication
Mummification of the body etc.
The methodologies of taking fingerprints have shown
considerable development. Initially the fingerprints and palm prints were
recorded using normal printer inks. Prints are also taken with other advanced
digital devices such as live fingerprint scanners.
How to take fingerprints of a dead body-
Depending on the time of Death we take fingerprints of a
dead body. If death is caused in shorter time this means that body is fresh then
it is easy to take prints otherwise it goes difficult.
The dead bodies divided
in to three categories as follows -
1. When body is fresh (died presently) and the rigor mortis
have not set in.
2. When rigor mortis has set in.
3. The dead body is in advance stages of decomposition.
1. When body is fresh (died presently) and the rigor mortis
have not set in –
Finger impression of the dead body where rigor mortis has not set in is quite simple just like as that of living person. Normal process and technique that are used for taking prints of living person are used. First one is to laid the deceased person face down and palm down on a table and printers inks applied on the fingers using slab one by one as we done in case of living person and take the prints on a paper. The fingers are flexible and it makes the finger impression easy to take. Second method is to use the inked roller and is rolled over the finger uniformly. A piece of white paper is attached to the shoe horn and prints taken on that paper. The paper is then removed from the shoe horn and it is pasted on the finger print slip at the particular box. You can also dust the fingers with black powder and apply the adhesive tape to finger ridges. When you peel the tape off you can get the finger impression, placed it on the white paper but consider that the impression of finger you get is a negative image of the fingerprint.
2. When rigor mortis has set in –
The rigor mortis starts from three hours after death. When
the rigor mortis is just started the fingers would become stiffened. To loosen
the stiffness one should make the movement of wrist and the fingers and take
fingerprints as the method discussed above.
When the rigor mortis is completely occurred and we want to
remove the rigor mortis then by submerging the hand and 1/3 of the lower part
of the forearm in hot water for a minute and continuously moving the wrist and
fingers rapidly. This process helps to overcome the rigor mortis. Hands will be
taken out and dried with towel. The hand of the dead body should be immersed up
to the wrist in the water. We have to immerse it the hand up to one minute if
the water is very hot. When the water is not very hot normally it is immersed
for two three minutes.
When neither the flexibility of the fingers nor the
movability of the wrist is achieved or the dead body is found with the hands
tightly clenched then we have to use force for straightening the fingers. A
scalp is used to make the deep cuts on each finger in the joints and then they
can be straightened. If the thumb is cramped or bent, it can be straightened by
making a deep cut between the thumb and index finger. After
straightening the normal method is used to take finger impressions.
3. The dead body is in advance stages of decomposition –
Depending upon the nature of decomposition following methods
has been used.
Sodium Hydroxide (NaOH) Solution
Method - In this method we take 1.3% of diluted NaOH in a
flask. Cut the first phalange of each finger. Immersed each finger separately
in diluted NaOH solution. After half an hour we have to see whether the
shrinking is disappeared or not, if it is not disappeared we have to immerse
the finger for another half an hour. After disappearing of skin shrinking we
can ink the finger and take the fingerprints.
There is a possibility of softening the ridges and slightly
the upper lair of the bulb starts tearing when fingers immerse in solution for
more than one hour. To make it harden we have to immerse the fingers in 3% of
mild solution of formaldehyde for few minutes. After that fingers are taken out
and dried to take ink fingerprints.
In advance stage of decomposition, putrification or when
body is softened or decomposed by water or burning or tip is wrinkled we use Plastic
regeneration Method.
Plastic regeneration Method -
In this method two things are used to take the finger
impressions of the decomposed body.
(i) Glycerinated Gelatin
(ii) Air
In the decomposed bodies on the fingers there is shrinking
of the tissues on the bulb portion of the fingers. In order to remove these
shrinkages we have to make use of glycerinated gelatin or air.
(i) Glycerinated Gelatin: Mixture of hot Glycerinated
Gelatin (seven part of Glycerin) and one part of Gelatin is injected in between
the nail and the skin for each finger. The mixture enters inside portions of
the bulb of the finger and remove the shrinking, then we can use ink and take
the finger impressions slowly on a piece of paper which is attached to the shoe
horn.
(ii) By Using Air: Air is also used for removing the shrinkness
on the bulb of the finger. 1 cc to one and half cc of air is injected for finger
then by applying the ink we have to take finger impressions slowly.
Xylene Solution: When
plastic regeneration and treating with sodium hydroxide is of no use then we
have to adopt this method. Xylene solution should be applied from time to time
to keep the skin smooth. When the skin is thin enough and sufficiently pliable
then skin is removed and is immersed in formaldehyde solution for few minutes
then it is taken out. The lair is then placed on the operator’s finger by
applying the ink we can take the finger impression on the paper.
Procedure for taking burnt dead body finger impression –
In burnt cases the epidermis becomes hard and partially
loose from the flesh. This upper layer is removed from the first phalange of
the finger and then inked print will be obtained in a regular way by placing
the skin on the operators own finger.
Sometimes direct digital photography is also used for taking
finger impression of dead body. Contactless scanners (capable of capturing the
finger pattern fully in three dimensions) are said to be in development but not
yet available.
A new technique called Thanatoprint is used for taking
finger impression of dead body.
Thanatoprint – This technique allows morphological reconstruction of advanced decayed corpses by extracting fluids from the body’s tissue and it restore the antemortem volume and tenseness. Fingerprints of high quality are gathered in this technique even in cases of advanced decay, by local application to a corpse’s hands.
MR. DEEPAK PAWAR has been working as Finger Print Expert / Police Officer in Finger Print Bureau , Delhi Police at New Delhi since 2001 . He is the senior most Finger Print Expert , attending / visited several scene of crime and solved many crime cases .He has passed M.Sc (Chemistry) and he is the Member of International Association of Identification . He is the Member of Delhi Police welfare association . He is supervising the Forensic , New Delhi District , Mobile Crime Team . He is one of the Expert in the Special Investigation Team held for investigation of important cases . He has been giving fingerprint proficient training to Delhi Police personnel's . He has been Presented / giving lectures on topics related to forensic science . He is also making examination paper of Finger Print proficient course . He is awarded with Police Medal by MHA and Delhi Police.