Forensics TSA v2

Transfer Stains

Object coming in contact with existing blood stains and leaving wipes, smears, or pattern transfers

Impact Stains

Blood projecting through air and usually seen as splatters. (May also include gushes, splashes, and arterial spurts.)

Gunshot Splatter

Includes forward splatter from exit wound and back splatter from entrance wound. Typically: Forward is a fine mist and the back is larger, fewer drops.

Arterial Spray

Spurt of blood when a major artery is severed with new pattern created each time the heart pumps

Expired Splatter

Blood from an internal injury mixing with air from lungs being expelled through the nose, mouth, or an injury to airways or lungs, forms a very fine mist and some blood stains are latent.

Sharp Force Injuries

Less blood being deposited on the instrument, smaller more linear patterns of stains

Blunt Force Injuries

Larger surface area will collect more blood, producing drops of various sizes.

Transient Evidence

Temporary evidence, is expected to degrade after a period of time. ex. odors, temperature, footprints

Exsanguination

Bleeding to death

Algor Mortis

Cooling of body after death

Lividity

Discoloration of the body after death. Takes minutes to an hour. Lasts for 36 hours

Rigor Mortis

Stiffening of a body after death. It takes about 4 hours after death

The Three Classifications of Traumatic Death

Suicidal, Homicidal, Accidental

The 5 Manners of Death

Natural, Accidental, Homicidal, Suicidal, Undetermined

Amount of teeth in an adult mouth

32

Forensic Pathology

Pathology that focuses on determining the cause of death by examining a corpse

The Primary Duty of a forensic expert in a court of law

The Primary Duty of a forensic expert in a court of law

To Tell the Truth. They have Legal Obligations to which they must conform their conduct

Public Science

What forensic science is often called

The meaning of the term "forensics"

Related to public or legal matters

Coroner

An Official who investigates sudden, violent, or suspicious death

Degree of Scientific certainty

The measurement of a conclusion drawn from scientific data

Gross Examination

Gross Examination

Deals only with what is visible to the unaided eye

Hair Cutting

Contains Mitochondria DNA

Circumstantial Evidence

Evidence that relies on an inference to connect it to a conclusion of fact—like a fingerprint at the scene of a crime. By contrast, direct evidence supports the truth of an assertion directly—i.e., without need for any additional evidence or inference.

Chromotography

Method used by scientists for separating organic and inorganic compounds so that they can be analyzed and studied

Retention Factor

The retention factor of a particular material is the ratio of the distance the spot moved above the origin to the distance the solvent front moved above the origin

Keratin

The protein that hair is primarily made of

Amount of ridges an adult human has on one finger

150

Percentage of arched fingerprints

5%

Percentage of looped fingerprints

70%

Percentage of whorl fingerprints

25%

How DNA is replicated in a laboratory

Using a polymerase chain reaction (PCR) sequence

Natural and synthetic

Two primary categories of fibers

Symptoms of Carbon Monoxide exposure

The victim would probably be dead. The skin would be pale or pink with the lips being bright red. Symptoms include headaches, weakness, vomiting, confusion, and loss of consciousness.

Ingestion, Inhaled, or Absorbed through skin.

Ways a person can get a toxin

Luminols

Locates blood in a crime scene even if it is cleaned up.

Hai Duan Yu

He wrote the first known book on Forensic Medicine autopsy.

GSR

Gun Shot Residue

preservatives

To prevent bacterial or fungal growth.

Cast-off

Results when an object sung in arc flings blood onto nearby surfaces. Tail points in direction of motion and the number of arcs can show minimum number of blows.

The cause of finger print ridge patterns

Amount and location of volmer pads in thick skin

Blow flies

The insect that is usually first to come in contact with the body

Whorl

Consists of a series of almost concentric circles.has two deltasFour types of these patterns

Arches

ridges flow in one side and flow out theopposite side. There are no deltas in this pattern*There are two types of these patterns

Loop

the ridges will flow in one side, recurve, touch or pass through an imaginary line drawn from the delta to the core, and exit the pattern on the same side as it entered.has only one delta.There are two types of these patterns

Fibers

are the smallest indivisible unit of a textile, it must be at least 100 times longer than wide. Fibers are twisted together to make up yarn.

Latent Prints

Not obviously visible. can only be seen with powder

Patent Prints

Visible prints

Plastic Prints

3D impression into an object (putty, butter, wax etc.)

Sources Of Residue

Oil on your fingers keep them lubricated and protected.1-2% of secretion is amino acids, salts etc.)

Percentage that leaves latent prints

85-90%

Non secretor

People who don't leave don't leave fingerprints

How to know which powder to use

1. color of surface2. texture of surface

Iodine Fuming

Chemical reaction with fats. MUST PHOTOGRAPH

Ninhydren

Reaction with aa's,, peptides and protesters

Super Glue Fuming

Heated and sticks to prints then hardens to a white film

Textile

A flexible, flat material made by interlacing yarns (or threads)

Crystalline

Fibers composed of polymers packed side by side in a repeated pattern, usually stiff and strong

Polymer

Term means, many parts

Monomer

Term means single part

Yarn

fibers that have been spun together

Direct Transfer

Is the transferring of particles or fibers when the suspect and victim come into direct contact

Secondary Transfer

When fibers are picked up by a victim at an earlier time and then transferred to a suspect

Natural Fibers

Are any and all fibers that originate from animals, plants and minerals taken directly from the ground.

Animal Fibers

These contain fur, hair, and webbing. They all contain proteins in their composition and have many uses including but not limited to clothing, carpets, drapes, and bedding. Although usually associated with hair or fur, some fabrics such as silk is woven from webbing from a silk worm.

Plant fibers

Fibers made up of plants cells. They are grouped by the part of the plant they come from, like seed, stem, fruit, and leaves.

Stem Fibers

Include hemp, jute, and flax

Mineral Fibers

Produced from industrial processing of mined materials. They include fiberglass and asbestos

Synthetic Fibers

Fibers made from petroleum based polymers or regenerated natural fibers.

Regenerated Fibers

Are those that are changed through chemical processing of natural cellulose fibers to form rayon and other light weight fabrics

Synthetic Polymers

Polymers that are made from petroleum products and are long polymers

Polyester

A common synthetic fiber used in many clothing types. Can be made with recycled plastics.

Nylon

breaks down easily in light and acids

Wrap

Longitude part of weave (stronger part of weave)

Refractive Index

This index is the measurement of how much light is bent when traveling through an object and into air.

Thread Count

In a woven fabric, the number of warp threads plus the number of weft threads per square inch. Example 100 warp threads plus 150 weft threads gives a thread count of 250.

Burn test

Reaction to heat, manner of burning, smoke color and odor, type of residue. Often synthetic fibers melt.

Gathering Fibers

Forensic scientists may use fiber vacuum, sticky tape or tweezers.

Disadvantages of Synthetic Fibers

They can deteriorate in bright sunlight and melt at a lower temperature than natural fibers.

Asbestos

The mineral fiber from this rock is used in break pads, fire retardant coatings, ceiling tiles, pipe insulation and more.

Weave Patterns

Plain, basket, satin, twill are common ones

Oldest Loom

4400 BC

Early Collection

Necessary because 95% of fibers are lost in the first 24 hours.

Weft

The term for the thread or yarn which is drawn through, inserted over-and-under, the lengthwise warp yarns that are held in tension on a frame or loom to create cloth

Secretor

People who leave finger prints

Passive Stains

Drops, Flows, and Pools, results from gravity acting

Gunshot Injuries

Mist like splatter caused by bullets entering and exiting a body.

Exsanguination

Bleeding to death

Sharp Instruments

Make incised wounds

Blunt Objects

Produce lacerations (deep cut or tear in flesh or skin)

How long Lividity Lasts

36 hours

Mechanism of death

The fashion of how the death came to be

Considered Trauma

Thermal, Mechanical, Chemical

most clear and distinct bite

A fresh bite into tissues containing lots of muscle

Defensive Bite Marks

Poorly defined bite marks associated with possible tearing of tissue and frequent occurring as multiple bites

Fundamental purpose of the criminal justice system

to protect the right of the accused