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REFLECTION/DO NOW:

WATCH THE FOLLOWING VIDEO ON BLOOD SPATTER AND IDENTIFY SOME OF THE DIFFERENCES THAT CAN BE SEEN IN THE TYPES OF PATTERNS THAT ARE SEEN WITH SPATTER.

ESSENTIAL QUESTION: WHAT ARE THE TYPES OF BLOOD SPATTER PATTERN?

PASSIVE BLOOD

SPATTER

THESE PATTERNS ARE FORMED SOLELY DUE TO THE EFFECT OF GRAVITY

TRANSFER

BLOOD SPATTER

PATTERNS FORMED SIMILAR

TO A STAMP TRANSFERING INK TO ANOTHER SURFACE.

THE OBJECT WILL LEAVE BEHIND THE IMPRESSION IN BLOOD

REFLECTION:ANSWER THE FOLLOWING QUESTIONS COMPLETELY. THIS WILL BE TURNED IN FOR A QUIZ GRADE.

1.TAKE THE 6 PATTERNS (IE. SMEARS, POOLS, SPURTS, ETC) AND MATCH THEM INTO THE PROPER MAIN CATEGORIES (PASSIVE, TRANSFER OR PROJECTED)

2. THEN FOR EACH CATEGORY PROVIDE A DRAWING OR AN EXPAINATION OF HOW THIS PATTERN WOULD BE CREATED/CAUSED.

ESSENTIAL QUESTION: WHAT ARE THE TYPES OF BLOOD SPATTER PATTERN?

The six patterns of blood spatter fall into 3 main categories

THESE PATTERNS ARE DUE TO FORCES THAT ARE GREATER THAN THE FORCE OF GRAVITY.

3 Categories

of Blood

Spatter

PROJECTED

BLOOD SPATTER

ESSENTIAL QUESTION: WHAT ARE THE TYPES OF BLOOD SPATTER PATTERN?

THESE FORCES CAN RESULT FROM OUTSIDE THE BODY OR FROM INSIDE THE BODY AND ALLOW THE BLOOD TO TRAVEL IN A PATH OTHER THAN DUE TO GRAVITY

POOLS FORM AROUND A VICTIM WHO IS BLEEDING HEAVILY AND REMAINS IN ONE PLACE.

  • Passive

  • Transfer

  • Projected

POOLS

IF THE BLEEDING VICTIM MOVES TO ANOTHER LOCATION, THERE MAY APPEAR TO BE DROPLETS OR SMEARING CONNECTING THE MULTIPLE LOCATIONS

ESSENTIAL QUESTION: WHAT ARE THE TYPES OF BLOOD SPATTER PATTERN?

ESSENTIAL QUESTION: How can drops help determine direction?

CAN BE LEFT BY A BLEEDING VICTIM AS HE OR SHE MOVES FROM ONE LOCATION TO ANOTHER

The shape of an individual drop of blood provides clues to the direction from where the blood originated.

TRAILS

DIRECTIONALITY

THE DROPLETS CAN VARY AND BE ROUND OR SMEARED OR EVEN APPEAR AS SPURTS.

THE POINT OF IMPACT OF THE DROP WILL BE DARKER THAN THE REST OF THE DROP AS IT WILL HAVE THE GREATEST VOLUME OF BLOOD

ESSENTIAL QUESTION: WHY DOES BLOOD ACT LIKE IT DOES?

THE DIRECTION OF FORCE IS ALWAYS IN THE DIRECTION TOWARD THE TAIL, OR SMALLER END OF THE SMEAR OR SPATTER

ESSENTIAL QUESTION: WHAT ARE THE TYPES OF BLOOD SPATTER PATTERN?

PROPERTIES

OF BLOOD

DROPLETS

ARE LEFT BY A BLEEDING VICTIM DEPOSITING BLOOD AS HE OR SHE TOUCHES OR BRUSHES OTHER OBJECTS, LIKE A WALL OR FURNITURE

SMEARS

ESSENTIAL QUESTION: WHAT ARE THE TYPES OF BLOOD SPATTER PATTERN?

THERE ARE 6 MAIN TYPES OF SPATTER PATTERN THAT WERE IDENTIFIED IN 1902

ESSENTIAL QUESTION: WHAT ARE THE TYPES OF BLOOD SPATTER PATTERN?

SPLASHES

THESE ARE SHAPED LIKE EXCLAMATION POINTS. THE SHAPE AND POSITION OF THIS PATTERN CAN HELP LOCATE THE POSITION OF THE VICTIM DURING THE ATTACK

ESSENTIAL QUESTION: HOW ARE BLOOD TYPING TESTS PERFORMED?

TYPES OF SPATTER PATTERN

ARTERIAL SPURTS/GUSHES

  • PASSIVE FALL
  • SPURTS AND GUSHES
  • SPLASHES
  • SMEARS
  • TRAILS
  • POOLS

ESSENTIAL QUESTION: WHY DOES BLOOD ACT LIKE IT DOES?

THESE ARE PATTERNS THAT ARE OFTEN FOUND ON WALLS OR CEILINGS THAT ARE CAUSED BY THE PUMPING ACTION OF THE HEART

DROPS OF BLOOD CAN HELP DETERMINE THE HEIGHT AND ANGLE THE BLOOD FELL FROM.

AGGLUTINATION

THE CLUMPING OF MOLECULES OR CELLS CAUSED BY AN ANTIGEN-ANITBODY REACTION

PROPERTIES

OF BLOOD

DROPLETS

OTHER PATTERNS SUCH AS SMEARS CAN TELL THE DIRECTION AND FORCE OF THE BLOW THAT CAUSED THE SPATTER

ESSENTIAL QUESTION: WHAT ARE THE TYPES OF BLOOD SPATTER PATTERN?

BLOOD FALLING DIRECTLY TP THE FLOOR AT 90 DEGREES WILL MAKE CIRCULAR DROPS, WITH SATELLITES.

ESSENTIAL QUESTION: WHAT IS BLOOD SPATTER?

PASSIVE FALL

IF A PERSON HAS THE PARTICULAR PROTEIN IN THEIR BLOOD CELLS, THE SAMPLE WILL CLUMP WHEN TESTED WITH THE ANTIGEN SERUM

In 1939 the meaning of the splatter pattern was first analyzed. It was first used in a criminal case in 1955 to exonerate a man accused of a violent crime

HISTORY OF

BLOOD SPATTER

THE FARTHER THE FALL FOR THE DROP THE LARGER THE CIRCLE AND THE MORE SATELLITES WILL OCCUR

ESSENTIAL QUESTION: WHAT ARE THE MAJOR BLOOD TYPES?

ESSENTIAL QUESTION: WHAT IS BLOOD SPATTER?

ESSENTIAL QUESTION: WHY DOES BLOOD ACT LIKE IT DOES?

ESSENTIAL QUESTION: WHAT ARE THE BASICS OF BLOOD SPATTER ANALYSIS?

It takes a grouping of blood stains to make a blood splatter pattern.

HISTORY OF

BLOOD SPATTER

WET BLOOD HAS MORE VALUE THAN DRIED BLOOD, BECAUSE MORE TEST CAN BE RUN ON IT.

When a wound is inflicted, a blood splatter pattern may be created.

ESSENTIAL QUESTION: WHY DOES BLOOD ACT LIKE IT DOES?

PROPERTIES

OF BLOOD

DROPLETS

Rh FACTOR IS ANOTHER BLOOD PROTEIN COMMONLY USED AS HUMANS EITHER HAVE THE PROTEIN OR DON'T HAVE IT

Blood Splatter Analysis

FOR EXAMPLE, ALCOHOL AND DRUG TEST CAN ONLY BE RUN ON WET BLOOD

Analysis of a splatter pattern can aid in determining the:

  • direction blood traveled.
  • angle of impact.
  • point of origin of the blood.
  • velocity of the blood.
  • manner of death.

IF ANY BLOOD DOES ESCAPE COHESION IT WILL CREAT SECONDARY DROPLETS CALLED SATELLITES

Blood cells and blood typing

ESSENTIAL QUESTION: WHAT ARE THE MAJOR BLOOD TYPES?

OTHER BLOOD PROTEINS USED IN BLOOD TYPING

PROPERTIES

OF BLOOD

DROPLETS

The pattern can help to reconstruct the events surrounding a shooting, stabbing, or beating.

ESSENTIAL QUESTION: HOW IS HUMAN BLOOD DIFFERENT THAN ANIMAL BLOOD?

ESSENTIAL QUESTION: WHY DOES BLOOD ACT LIKE IT DOES?

IF YOU DONT HAVE IT YOU ARE Rh - AND IF YOU HAVE IT YOU ARE Rh +. ABOUT 85% OF HUMANS ARE Rh +

ESSENTIAL QUESTION: HOW DO SCIENTISTS USE BLOOD EVIDENCE?

ESSENTIAL QUESTION: WHAT ARE THE BASICS OF BLOOD SPATTER ANALYSIS?

ESSENTIAL QUESTION: WHAY DOES BLOOD ACT LIKE IT DOES?

MOST VERTEBRATES HAVE ESSENTIALLY THE SAME BLOOD CELLS, WITH RED AND WHITE BLOOD CELLS AND PLATELETS.

WHY IS BLOOD TYPING COMMONLY USED IN CSI?

SINCE BLOOD IS COHESIVE AND FORCES ACT TO KEEP IT TOGETHER, DROPLETS RESITST FLATTENING EVEN AFTER HITTING A SURFACE (FIGURE 3)

BLOOD FORMS DROPLETS AS IT FALLS, DUE TO COHESION AND MOLECULES STICKING TOGETHER (FIGURE 1)

CAN BE ANALYZED TO DETERMINE BLOOD TYPE AND DNA, WHICH CAN BE MATCHED TO A GROUP OR INDIVIDUAL SUSPECTS

THE PATTERNS LEFT BY FALLING BLOOD, OR SMEARED BLOOD HELP THE CSI INETRPRET AND RECONSTRUCT WHAT HAPPENNED AT A CRIME SCENE

RELEVANCE OF BLOOD SPATTER

EVIDENCE

Given the frequency of different genes within a population, it is possible to determine the probability that a particular blood type will appear in a particular population or ethnicity/culture.

BLOOD SAMPLES

PROPERTIES

OF BLOOD

DROPLETS

ESSENTIAL QUESTION: WHAT IS BLOOD MADE OF?

PROPERTIES

OF BLOOD

DROPLETS

THIS ALSO WILL RESULT IN THE ROUND SHAPE OF THE DROPLET ITSELF

MOST INVERTEBRATES HAVE AN OPEN CIRCULATORY SYSTEM THAT HAS ONLY ONE TYPE F CELL IN THE "BLOOD".

AS A RESULT GRAVITY ACTS ON DROPLETS AS THEY FALL AND MAKES THE DROPLET LONGER THAN IT IS WIDE. (FIGURE 2)

ESSENTIAL QUESTION: WHAT ARE THE MAJOR BLOOD TYPES?

VERTEBRATES

VS. INVERTEBRATES

CAN BE ANALYZED TO GIVE CLUES TO THE LOCATION OF A CRIME, MOVEMENT OF A VICTIM, AND TYPE OF WEAPON USED

BLOOD DROPLETS

Blood typing is quicker and less expensive than DNA profiling.

DIFFERENCES BETWEEN VERTEBRATES RANGE FROM THE TYPE OF ANTIGENS TO WHAT THE MATURE RED BLOOD CELLS LOOK LIKE.

BLOOD SPATTER

CAN BE ANALYZED TO DETERMINE PATTERNS THAT GIVE INVESTIGATORSCLUES TO HOW A CRIME MIGHT HAVE HAPPENNED

WHY IS BLOOD TYPING COMMONLY USED IN CSI?

THE CLOSER THE ANIMALS ARE IN TERMS OF ANCESTORS, THE LESS DIFFERENCES THERE ARE

ESSENTIAL QUESTION: WHAT IS BLOOD MADE OF?

It produces class evidence but can still link a suspect to a crime scene or exclude a suspect.

Whole blood carries cells and plasma—the fluid with hormones, clotting factors, and nutrients.

EACH BLOOD CELL PERFORMS A DIFFERENT IMPORTANT FUNCTION

Composition of Blood

ESSENTIAL QUESTION: WHAT ARE THE MAJOR BLOOD TYPES?

THERE ARE 4 MAJOR TYPES:

  • A, B, AB, AND O

WHAT ARE THE FREQUENCIES OF BLOOD TYPE IN THE HUMAN POPULATION?

Red blood cells carry oxygen to the body’s cells and carbon dioxide away.

REFLECTION/DO NOW:

ANSWER THE FOLLOWING QUESTIONS USING YOUR NOTES AND IN COMPLETE SENTENCES.

1. WHY IS BLOOD TYPE CONSIDERED "CLASS EVIDENCE"?

2. HOW IS THIS DIFFERENT THAN

DNA PROFILING?

White blood cells fight disease and foreign invaders and, alone, contain cell nuclei.

Composition of Blood

IN YOUR NOTES ANSWER THE FOLLOWING QUESTION:

WHICH BLOOD CELLS CONTAIN DNA AND WHY?

PLASMA IS SIMILAR TO SALT WATER IN COMPOSITION AND CONTAINS:

  • REB BLOOD CELLS
  • WHITE BLOOD CELLS
  • PLATELETS

Platelets aid in blood clotting and the repair of damaged blood vessels.

ESSENTIAL QUESTION: HOW CAN BLOOD BE USED AT A CRIME SCENE?

ESSENTIAL QUESTION: WHAT ARE THE MAJOR BLOOD TYPES?

Future Directions

YOUR BLOOD TYPE IS BASED ON THE PROTEINS THAT ARE FOUND IN YOUR BLOOD

How do you get your blood type?

THESE PROTEINS ARE FOUND IN THE MEMBRANE OF YOUR RED BLOOD CELLS

Characteristics of Saliva and Semen

Determining the area of hemorrhage

Blood typing can provide class evidence; whereas DNA profiling can provide individual evidence.

Drugs and Posions

  • Hopefully a means to determine age of bloodstains will be discovered
  • Technological ways of speeding up and improving ways of analyzing and interpreting blood spatter patterns
  • Area of hemorrhage- “blood loss began here”
  • There are five principle methods of determining the area of hemorrhage and the position of the person at the time they were struck.
  • Observation
  • Trigonometry
  • Stringing
  • Graphics
  • Computer programmes

The antigens in the ABO system are the most common antigens found on red blood cells.

• A persons red blood cell may possess either only A antigens and B antigens both classes A and B (type AB) or neither class A or B antigens (O).

• People who are type A tolerate their own class A antigens but produce antibodies against B antigens. This causes red blood cells to clump together.

• Type B people produce antibodies against class A antigens,

• Type AB produce neither class A or B antigens, and type O produce antibodies against both class A and class B antigens.

Blood cells and blood typing

  • Normally use urine to analyze for drugs and poisons, but feces can be used
  • Some circumstances may not mean poisoning

Methods for detecting blood

HISTORY

AND INTRO TO

BLOOD

Infrared imaging

A blood spatter pattern can give information about the truthfulness of an account by a witness or a suspect.

  • Presumptive tests-most work on the basis of hemoglobin catalysis
  • The oxidation of an oxidant (hydrogen peroxide) and the products of oxidation then interacting with other chemicals bring out the color change.

Characteristics of Saliva and Semen

Saliva and Semen As Forensic Indicators

Demonstrating the Presence of Saliva and Semen

Semen

Saliva

  • Semen is often analyzed in rape and sexual assault cases
  • Great source of DNA
  • It can be released after death, so one must use caution and not assume the presence of semen means a sexual act
  • Both fluoresce in UV light
  • Many items also fluoresce, use discretion
  • Commercial semen detection tests
  • PSA acid phosphatase test
  • "Christmas tree test"
  • Produced by salivary glands
  • can be found using a specific assay method to detect amylase activity (ELISA)
  • Forensically important: bite marks, spit, good source of DNA sample (mouth swabs), many drugs can be detected in saliva
  • Demonstrates latent blood without chemicals.
  • Video or camera must measure wavelengths in the 760-1500nm region.
  • Development stage
  • If the background has the same infrared absorbency and reflectance characteristic as the bloodstain.

  • 75-85% of population are "secretors", allows for serological profiling
  • Use of DNA
  • Spermicidal condoms

It also can provide information about the origin of the blood, the angle and velocity of impact, and type of weapon used.

Laser Microdissection

Extracting DNA From Feces

Computer Programs

ESSENTIAL QUESTION: HOW CAN BLOOD BE USED AT A CRIME SCENE?

Trigonometry

  • The use of computer programs like Hemospat and BackTrack to analyze bloodstain distribution is rapidly replacing the use of manual methods like stringing

Titanium dioxide

BLOOD HAS BEEN STUDIED FOR 1000S OF YEARS AND ADVANCEMENTS HAVE LED TO IT BEING ONE OF THE BEST FORENSIC TOOLS

  • Relatively difficult because feces contains substances that interfere with the techniques normally used for extraction and analysis
  • QIAGEN QIAamp DNA Stool Mini Kit available and reliable
  • Urine does not normally contain enough cells for DNA profile, though possible
  • Women's profile easier to make
  • Basic trigonometry-
  • If a blood droplet hits a smooth clean flat surface at 90° it will form an oval shape with about the same diameter as the droplet and with a number of spines dependent upon the velocity with which it impacted and the nature of the surface it hit.
  • strikes the surface at an angle, it will form an ellipse the length.
  • Angle θ = angle of impact (θ = Greek symbol ‘theta’)
  • Sine of angle θ=(Width of stain)/(Length of stain)

  • A 10% w/v solution of titanium dioxide in methanol is sprayed onto suspected area.
  • Acts as a white dye
  • Works well on dark surfaces.
  • Spray is flammable and poisonous.
  • Not suitable to use in crime scene.

Types of bloodstains

Additional Information

Hemospat

Benefits To the Use Of Computer Programs

  • Hope for use of three-dimensional laser scanners
  • This use would simplify the current process as well as aid in complex situations

Interpreting bloodstains

Stringing

  • Rapid analysis
  • Numerical estimates of error
  • Recording of data more scientifically rigorous
  • Easier to understand event reconstruction
  • Facilitates the presentation of evidence in court

After scene is recorded

On a vertical surface an arrow indicating up/down is required, arrow should be drawn 90 vertically downward. (plumb line)

“Level line” is drawn underneath the stain.

Elastic cord is placed through mid-line of each stain and runs backward in the direction it came from.

Angles formed can be recorded using protractor “direction of flight angles”

  • Stains must be noted in the exact position, size, shape and the nature of the material.
  • From the distribution and shape of the stains it can be determined how the blood was shed and the wound that was inflicted.
  • Above certain height it is impossible.
  • Large droplets develop a terminal velocity greater than small ones.

How It Works

  • Spatter stains: subdivided into three categories based upon their cause:
  • secondary mechanism
  • impact mechanism
  • projection mechanism.

Luminol

Second:

First:

Third:

Fourth:

  • The crime scene is recorded using a pre-calibrated digital camera, a scale with each photograph, and a directional indicator
  • Finally, after several other bloodstains have been analyzed, the computer can generate lines to identify the area of origin of the stains in either 2D or 3D
  • The computer then superimposes an ellipse over any chosen bloodstain and identifies the angle of impact by using algorithms
  • In some programs, a calibrated pattern such as a checkerboard in the photographs allows the angled shots to be changed by the computer to look as if they were taken from overhead
  • Luminol is mixed with sodium carbonate to form alkaline solution whilst a separate solution of either sodium perborate or hydrogen peroxide act as the oxidant.
  • If hemoglobin present, the oxidant is broken down and highly reactive free oxygen radicals are formed.
  • Reaction gives a blue glow that can be seen in dim lights.
  • Very sensitive, blood can be detected even on washed clothes.
  • The luminescence does not last long.

Post Mortem Toxicological Analysis of Blood

Secondary mechanism

Impact mechanism

Projection mechanism

Problems with presumptive test

Altered stains

  • Drugs redistribute their concentrations at different sites in a non uniform manner after death
  • No way of determining tolerance after death
  • Caution must be used with any findings

Kastle-Meyer Test

  • All of the tests suffer from common environmental chemicals that also break down the reaction.
  • False positives occur:
  • Potatoes, horseradish, red onions
  • Inorganic substances: ferric sulphate
  • Always perform a negative control and positive control.

Urine and Feces as Forensic Indicators

  • Any blood stain can become altered at some point after its initial formation.
  • Blood stains fall on one another.
  • Blood dries out and clots
  • Attempting to clean or movement of insects.
  • Body being dragged will leave clots of blood the drag pattern.

  • When positive it will be a pink color.
  • Slightly less sensitive than luminol and must not be performed directly on the stains as it could interfere with DNA extraction.
  • A sample of the stain is scraped onto filter paper and treated with a drop of ethanol.
  • A drop of phenolphthalein, hydrogen peroxide are added.
  • If color change before hydrogen peroxide it is negative.

  • Feces can provide DNA, health, diet, and where a person has been
  • Useful even if dried out or extremely old

Vitreous Humor

Graphics

Diet

Health

Artificial Blood

  • Form, texture, color, and smell of feces can provide information about heath
  • Eggs and cysts of parasites can give prior visited locations
  • Can show underlying health conditions
  • Indigestible plant material can show a person's diet and show where a person has been
  • Animal material can be used to identify diet
  • Specific animal that was consumed can be identified by analyzing for specific myoglobin
  • Mineral material can give geographical location

Types of bloodstains

  • Experiments are used to verify conclusions that are controversial
  • "Recipe" used is stored at room temperature
  • "Recipe" comes from Millington (2004)
  • Passive stains: these are subdivided into
  • Drops
  • Flows
  • Transfers
  • Large volumes

Post Mortem Toxicology

Estimation of the Post Mortem Interval

Transfer

Drops

  • Wet blood is transferred from one object to another.

Flows

Large volume

  • Blood flows passively to produce small rivers or streams of blood
  • Rise in potassium ion concentration in vitreous humor after death
  • Different techniques of reaching measurement
  • Useful in first 24 hours after death
  • Useful for burned bodies
  • Many drugs can be detected in vitreous humor
  • Less susceptible to chemical and microbial decay
  • Often used for ethanol analysis
  • Drawback is limited information on many drugs post mortem level in the vitreous humor and ante mortem level in the bloodstream

Formula For Artificial Blood

Sudden Infant Death Syndrome

  • Hypoxanthine levels in vitreous humor elevate in SIDS cases
  • Still under scrutiny
  • 13g of superfine self-rising flour
  • 1g of sodium chloride
  • 1ml of Glycerol
  • 1ml of Strawberry sugar syrup
  • 1ml of scarlet food coloring
  • 183ml of distilled water

Saliva and Semen

Blood and Blood Spatter Analysis

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