Drill

 Why is blood typing a class evidence?

 How is forensics biology different from forensics serology?

 Define whole blood.

 What are the formed elements of blood?

Drill

  Objective(s) Explain and do a Blood Spatter analysis.

Collection, Preservation & Packaging of Biological Evidence

Drill

 Define antibodies & antigens. How are they different?

 Name two things that can be determine from a blood splatter pattern.

 Name & describe 3 out of the 6 splatter patterns.

Blood & Physiological Fluid Evidence

Chapter 8

Blood and Blood Splatter

 explain the composition of blood  describe the function of blood cells  determine the blood type of a blood sample  conduct a blood splatter analysis  examine wounds and describe the nature of the weapon  find and process blood evidence

Introduction and History

    Blood typing can provide ______________; whereas DNA profiling can provide ________________________. A _______________pattern can give information about the truthfulness of an account by a witness or a suspect.

It also can provide information about the ______________ of the blood, the angle and velocity of impact, and type of weapon used. Our understanding of blood began in _______ times and continues to grow today.

Forensics biology Preliminary examination of biological evidence in blood transfer and sexual assault cases, much that goes on the ___________________________.

Forensics Serology – Preliminary examination and genetic typing of biological evidence in blood transfer and sexual assault cases ________________analysis was available.

Review

 What is the difference between forensics biology and forensics serology?

 What kind of evidence can blood typing provide for court?

Nature of Blood 1. Only _________________ tissue in the body.

2. Made up of several cell types; ________________(erythrocytes) __________(leukocytes), and __________.

3. _______________ – blood serum protein 4. _______________________ - antibodies



Composition of Blood

_______________

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

________________

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

_________________

fight disease and foreign invaders and, alone, contain cell nuclei. 

______________

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

Function 1. ________________________through out the body.

2. Transfers _________________ throughout the body.

3. _________________.

4. ____________________ Amount of cells in blood ______ million RBC per cubic millimeter ____________ WBC per cubic millimeter ___________ mg/mL albumin ___________ mg/mL Immunoglobulin's

Review

 Name two functions of blood?

 What are the parts of blood with their function?

1.

Tube of blood is drawn and allowed to ______ for a few minutes for ________________.

2.

Blood will ____________ and become a dark red and fall to the bottom.

3.

_______ is on _____ is yellowish and contains dissolved proteins and other compounds.

4.

________ – same as serum but contains the clotting protein.

Blood Typing—

Proteins

42% of the population in the United States (of which 85% is Rh+) 12% 3% 43%

Blood typing is _________ and less expensive than DNA profiling. It produces class evidence but can still link a suspect to a crime scene or exclude a suspect.

Review

 What are the four blood types for humans?

 Which type is most common?

 Can a blood type convict a suspect?

Blood Typing—

Antibodies; Additional Proteins and Enzymes

    ____________ are proteins secreted by white blood cells that attach to antigens to destroy them. ____________ are foreign molecules or cells that react to antibodies. ____________ are complex proteins that catalyze different biochemical reactions. Many enzymes and proteins have been found in the blood that are important for identification purposes.

Blood Typing—Probability and

Blood Types

 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 _____________________________.  To determine the probability of two separate events, it is necessary to multiply their individual probabilities.  By identifying the additional proteins in the blood evidence sample, investigators can limit the size of a suspect population and help identify a suspect.

Blood Splatter

    In 1939 the meaning of the splatter pattern was first analyzed. When a wound is inflicted, a blood _____________ pattern may be created. It takes a _____________ of blood stains to make a blood splatter pattern. The pattern can help to _______________the events surrounding a shooting, stabbing, or beating.

Blood Splatter Analysis

Analysis of a splatter pattern can aid in determining the: ________________________________. ________________________________. ________________________________. ________________________________.

Blood Splatter Analysis

 When blood falls from a height or at a high velocity, it can overcome its natural cohesiveness and form ________________________.  When it falls onto a less-than-smooth surface, it can form

________________

around the drops.

Blood Splatter Analysis—

Six Patterns

Describe each of these: a. ______________ b. ______________ c. ______________ d. ______________ e. ______________ f. ______________

Blood Splatter Analysis—

Impact

Patterns can help investigators determine the ___________________ of weapon used.

– What kind of a pattern is produced by a gun shot? – What kind of a pattern is produced by a hammer blow?

Blood Splatter Analysis—

Directionality

The _________________ of an individual drop of blood provides clues to the direction from where the blood originated. How will the point of impact compare with the rest of a blood pattern?

Blood Splatter Analysis—

Location of the Origin of the Blood

  Draw straight lines down the axis of the blood splatters. Where the ____________________, the blood originated.

Review

 1. How can blood splatter determine direction?

 2. How can blood splatter determine location/origin of the blood source?

1.

2.

3.

Crime Scene Investigation of Blood

a.

b.

Search for blood evidence. If any is discovered, process it determining: Whether the evidence is ____________. Whether the blood is _________________. c.

The blood ___________________. Interpret the findings: a.

b.

c.

See if the blood type matches a ________. If it does not,_____________that suspect. If it does, decide if ___________is needed

Collection, Preservation & Packaging of Biological Evidence

__________________, Exemplar, Reference are known sources of biological evidence.

Collected in a ___________________.

The ______ of the stopper is an indicator of the _________ used. _______ is most common (ene top.

d iamine t etraaceitic acia) in a purple Can get DNA from many other places; Cheek (Buccal)

Review

 How is a known control different from an alternative control?

 Why is a blank control used?

 Name 2 out a 3 guidelines for crime scene investigation.

Biological Evidence from Scenes

_______ items with blood.

Fresh or Wet – clean spoonlike utensil.

Dried – Cutting, swabbing, scrapping, and elution (dissolving).

Ensuring that the evidence is ___________________before it is package and stored in a dry cool place.

Package in paper containers that can “___________”, never is an air tight container.

Testing

___________________– specimen from a known source.

_____________________– specimen obtained that might be the source of evidence.

_____________________– a clean sample containing no specimen.

Forensics Identification of Blood

________________(Screening) - for screening specimens that might contain substances or materials.

False-positives or false-negative Ideally preliminary test should give a _________ false negatives to ________ this test as a screening tool.

Testing

______________________– A sample of material on which biological evidence is deposited.

___________________ – unintended or potentially unrecognized, biological material in or on biological evidence, which could cause difficulty in interpreting the results.

Forensics Identification of Blood

__________________– More complicated and requires more time than a preliminary test.

Entirely specific for the substance or material for which they are intended.

A positive confirmatory means it is unequivocal demonstration that the specimen contains the substance or material.

No confirmatory test is available for blood – most the analyst can say is “might or could have”.

Forensics Identification of Body Fluids

Semen Male reproductive fluid.

Spermatozoa – ______ ________ million sperm per milliliter.

Seminal Plasma fluid that suspends sperm.



Semen is associated with sexual assault cases.

Somewhere in America, a woman is raped every ____ minutes, according to the U.S. Department of Justice.

 In 1995, _______ women were the victims of a rape or sexual assault. (NationalCrime Victimization Survey. Bureau of Justice Statistics, U.S. Department of Justice, 1996.)  Over the last two years, more than _________ women were the victim of a rape or sexual assault. (National Crime Victimization Survey. Bureau of Justice Statistics, U.S.Department of Justice, 1996.)  The FBI estimates that ____ of every _____________ females in the United States were raped last year. (Federal Bureau of Investigation, Uniform Crime Statistics, 1996.)

 Approximately______ of victims are raped by husbands or boyfriends, _____ by acquaintances, and _____ by other relatives. (Violence against Women, Bureau of Justice Statistics, U.S. Dept. of Justice, 1994)  The FBI estimates that only ______ of all rapes are reported to the police. U.S. Justice Department statistics are even lower, with only _________ of all rapes or attempted rapes being reported to law enforcement officials.

       ____ of every ____ rapes take place in a public area or in a parking garage. _____ of female victims reported that the offender was a stranger. _____ of rapes occur between the hours of ___ p.m. and ____ a.m. At ______of rapists were under the influence of alcohol or drugs. In _____of rapes, the offender used a weapon. In _____of rapes, the victim sustained injuries other than rape injuries. ______ of female rape victims require medical care after the attack.

Semen shines fluoresce brightly when exposed to ________.

Preliminary & confirmatory test for semen stains – same as blood testing.

______________________________ male prostate gland.

is a color test for the enzyme produced by the

Evidence collection and sexual assault cases

Rape Kits

DNA profiling

Investigation

Cases often succeed or fail on the __________ of the parties, since there is rarely a witnesses.

Injuries are properly _______________ and helpful in some cases.

Identification of Saliva and Urine

Saliva is produced by three gland that empty into the mouth cavity that contain a large amount of _________ .

Tests for amylase Dyed starch Radial enzyme diffusion ____________ animals, therefore it is not confirmatory only indicative.

is found in many plants and

__________ – contains several substance in large quantities.

Many animals produce urine, therefore it is considered the same as saliva.

. . . . . . . . . . . . . . . . . Summary

    Blood consists of cellular components and plasma. The various human blood types are caused by the presence or absence of A or B or both A and B proteins on the surface of red blood cells. Blood splatter evidence can be used to recreate a crime scene. Investigators endeavor to (a) locate, (b) identify, and (c) interpret blood splatter patterns at crime scenes.