biologicals


CHAPTER 5: Preservation of biological fluids blood saliva semen and other body fluids in crime scene
When you find blood stains, how will you collect and what information can you get from such stains?
Blood stains may be located at the crime scene. On the victim and the accused or on the weapon. When dead body is dragged blood stains may be found along the route.
In the process of forcible entry the accused may get hurt and his blood stains may be there at the place of occurrence and route his retreats by.
Io should look in
The corner of the walls.
Floorings joints and cracks
Walls doors furniture legs etc
Blood stains in shape of drops smears spatter pool indicate the origin from where they strike the surface.
Information to be known from the stains:
Whether the stain in question is blood
If it is blood what is its origin
If it is animal blood can the species of the animal be identified
If its human dies it belong to male or female
What is the blood group of the stain
Whether the paternity in case of dispute be established.
In what types of cases are you likely to find seminal stains? What articles will you examine and how? What care will you take while packing and forwarding such stains?
o Seminal stains are encountered in sexual offences like rape sodomy bestiality incest and other unnatural offences.
o These stains may be found on the clothing of the victim accused and at the scene of crime and offer important clues to prove sexual contact and give genetic character of the rapist.
o The wearing apparel of accused victim before washing and immediately after occurrence
o The material objects collected from both accused and victim like exchanged pubic hair nail vaginal swabs and slides semen saliva and blood
o While packing the stains ensure their proper drying under shade pack each article separately with neat label.
o Control blood semen samples in a properly preserved and packed manner need to be submitted.
o While folding the garment ensure not to fold in the region of stains.
Guidelines for IO in case of semen: Examine the scene of offence for
•any evidence of struggle like disarrangement of furniture and bed clothing, broken glass bangles, trampling of grass, of out door and also for loose hair, fibre, buttons and stains of blood, semen, faeces and mud. Avoid delay in sending the victim and the accused if apprehended for medical examination.

Delay could lead to loss of evidence due to passage of time; inadvertent acts of the victim; deliberate effacement of evidence by the accused and send as soon as possible the articles seized by the IO , Bed clothes stained, with semen/blood , and the material preserved by the doctors like vaginal swabs, pubic hair, nail clippings to FSL for necessary examination by the experts.
IO must be very careful not to contaminate samples with their own body fluids ,avoid rubbing, folding or wrinkling the stained area ,pack separate to avoid contamination ,suspects spittle(secretor status) In certain cases stains may be present on pieces of material or hand kerchiefs used by the victim after assault for cleaning purpose . Vulval pads and vaginal tampoons should be preserved for chemical analysis. Clothes are very important in corroborating or contradicting her story.

Chapter 6:
Preservation of wood hair insects and other biological material in the crime scene
How will you collect and preserve hair samples?
· Collect with clean fingers.
· Put into clean covers.
· For easy collection use transparent tape.
· Record the location.
· For sample hair from suspect or victim search their bodies thoroughly. Comb head hair onto a paper/ cloth.
· Hair from mustache and beard in separate clean covers.
· Number of 15 hairs from each region.
· In case of sexual assault comb and collect loose hair in pubic region.
· Pack it separately and individually.
· Hair from pubic region of both victim and assailant needed.
· Hair on crime weapon if possible should be sent after through drying of the blood adhering to it.
Where will you find fibers how will you collect them and how does fiber identification help the IO?
· Fibers are encountered as evidence in offences against persons.
· In murder/ sexual assault fibers from clothing could be exchanged between the assailant and the victim
· In road accidents fibers from the clothing of the victim may be transferred to the front portion of the vehicle.
· In a forcible entry through a ventilator/ window the fibers from the garments of culprit may be transferred to window or fibers from the carpet could be transferred to the foot wear of the culprit. Thereby establishing the association between the culprit and the victim or the crime scene.
· In case of use of fire arm in murder/ suicide fibers of the garment get sucked into the barrel thus establishing the involvement of that weapon in the crime.
· Fibers from floor – use clean broom /vacuum cleaner.
· Collect in a clean paper placed in a cover.
· The wearing apparel of both accused and victim are collected and separately packed.
· Collection should be done as early as possible.
· Packing should be proper with label.
What is forensic entomology? And how will you make use of it in crime investigation?
· Forensic entomology deals with the determination of time of arrival and recognition of different types of insects on a dead body followed by the growth and development of the off-springs on and around the dead body. The entomologists were asked to correlate the identification of insects with the time since death.
Diatoms: the presence of diatoms is a pathagnomic of drowning. Presence or absence of diatoms in the marrow of long bones is an indication of ante mortem drowning and / or post mortem drowning. If the same type of species are detected in both the marrow of the long bone and the site of drowning the site of drowning is confirmed. As the diatoms resist putrefaction and acid digestion they are best preserved even in decomposed bodies.