Final Exam

WHAT IS MEANT BY A "TRAWL" OF CODIS?

"FISHING WITH A NET" EVERY PROFILE IN THE DATABASE IS COMPARED WITH EVERY OTHER PROFILE AS OPPOSED TO COMPARING A SPECIFIC SUSPECT'S DNA TO THE CRIME SCENE EVIDENCE

• WHAT PRECAUTIONARY MEASURES SHOULD A CSI TAKE AT A CRIME SCENE WHEN HANDING EVIDENCE THAT WILL GO TO THE LAB FOR DNA ANALYSIS?

- DNA EVIDENCE IS EASY TO CONTAMINATE. DO NOT SMOKE, EAT, DRINK, SNEEZE! COUGH!, ANY ACTION THAT COULD CONTAMINATE DNA EVIDENCE AT CRIME SCENE. THE SAME APPLIES TO THE CRIME LAB, BUT WE (CSI) HAVE NO CONTROL OVER THAT

• CAST-OFF STAINS....WHAT ARE THEY? HOW CAN WE DETERMINE THE MINIMUM NUMBER OF BLOWS A VICTIM SUSTAINED? WHAT MAY WE DETERMINE BY THE SIZE OF THE BLOOD DROPS, WHICH OF THE TWO ARC-LIKE PATTERNS HAVE THE MOST BLOOD.....

BLOOD RELEASED OR THROWN FROM A BLOOD-BEARING OBJECT THAT IS IN MOTION...LIKE A BASEBALL BAT OR A GOLF CLUB THAT A SUSPECT IS SWINGING DURING THE ASSAULT. THE SIZE OF THE DROPS ARE DIRECTLY RELATED TO THE SIZE OF THE POINT FROM WHICH THEY WERE PROPELLED: DROPS FROM A SMALL, POINTY SURFACE (KNIFE BLADE) ARE SMALL AND LINEAR (NOT WIDE). DROPS FROM A LARGE, BLUNT SURFACE (BASEBALL BAT) ARE LARGER & WIDER

• WHAT HAPPENS DURING AN AUTOPSY? WHY IS IT IMPORTANT FOR A CSI AND/OR THE LEAD DETECTIVE TO ATTEND THE AUTOPSY? WHAT DOES THE CSI DO.......LEARN?

A SURGICAL PROCEDURE, PERFORMED BY A FORENSIC PATHOLOGIST TO DETERMINE THE CAUSE AND MANNER OF DEATH IN A SUSPICIOUS DEATH, IT IS IMPORTANT THAT THE POLICE ATTEND THE AUTOPSY BECAUSE PHYSICAL EVIDENCE MAY BE RECOVERED AT THAT TIME AND BECAUSE THE M.E. MAY HAVE AN EXPERT OPINION AS TO THE CAUSE, MANNER AND TIME OF THE VICTIM'S DEATH. IMPORTANT FOR INVESTIGATOR TO BE PRESENT AT AUTOSPY TO: GATHER INFORMATION GATHER PHYSICAL EVIDENCE DOCUMENT / PHOTO CONDITION OF BODY AND INJURIES LEARN CAUSE AND MANNER OF DEATH

• WHAT ARE THE 4 DIFFERENT BASES (YOU ONLY NEED TO REMEMBER THE LETTERS, NOT THE WHOLE NAMES) AND WHICH ALWAYS PAIRS WITH WHICH? (COMPLEMENTARY BASE PAIRING)

A-T-C-G

• A VICTIM IS SHOT IN THE CHEST WHILE WEARING A SHIRT. SPECIFICALLY HOW IS THE SHIRT PACKAGED TO SEND IT TO THE LAB?

AIR DRY ANY WET CLOTHING, NEVER CUT OUT THE AREA AROUND THE BULLET HOLE, FOLD IT IN SUCH A WAY AS TO PROTECT THE AREA WHERE THE BULLET HOLE APPEARS, PLACE CRAFT PAPER IN THIS FOLDED AREA TO PREVENT A CROSS-TRANSFER TO A DIFFERENT AREA

Why is it difficult to see all the individual striations from the bullet recovered at the crime scene; or from the victim's body, compared to the test fired bullet

AS THE BULLET PASSES THROUGH THE BARREL OF THE GUN (BORE), ITS SURFACE IS IMPRESSED WITH THE RIFLED MARKINGS OF THE BARREL. THIS ENABLES A FIREARMS EXAMINER TO CONCLUDE THAT A PARTICULAR BULLET WAS FIRED FROM A PARTICULAR GUN. AS IS THE CASE WITH EVERYTHING....A LAB CAN IDENTIFY SOMETHING ON ITS OWN.....BUT A LAB CANNOT CONDUCT A COMPARISION WITHOUT A KNOWN, STANDARD, REFERENCE SAMPLE.

What are striations

Are very fine lines that run the length of the lands & grooves. They are impressed into the metal and are minute imperfections found on the rifling cutter's surface. Or they are produced by tiny chips of steel that were pushed against the bore by the broach cutter as it cut through the barrel

What happens to a bullet, insofar as striations are concerned, when it passes through the barrel of the gun?

As the bullet passes through the barrel of the gun (bore), its surface is impressed with the rifled markings of the barrel. This enables a firearms examiner to conclude that a particular bullet was fired from a particular gun

• WHAT ARE THE 2 TYPES OF DNA TYPING/PROFILING? (YOU NEED ONLY KNOW THE ACRONYMS)

The Two type of DNA typing is RFLP (restriction fragment length polymorphisms 1984) and PCR (polymerase chain reaction 1990)

How is a gun barrel made?

The barrel of a gun is made from hollowing-out a bar of solid steel with a drill called a broach cutter. This drill leaves microscopic marks left behind on the inside of the gun barrel. The marks are randomly irregular and make each and every gun barrel unique

What is the definition of trajectory

The flight path of a moving object through space.

GSR IS OFTEN DEPOSITED ON A SHOOTER'S HANDS. WHAT CAN WE DO TO TEST A SUSPECTED SHOOTER'S HANDS FOR GSR? IS THERE A TIME FRAME TO DO THIS?

we swab the hand of the suspect Yes there is time frames because it ONLY COLLECT AND SUBMIT A RESIDUE SAMPLE TO THE LAB FROM A SUSPECT IF YOU ARE ABLE TO COLLECT IT WITHIN 5-6 HOURS AFTER THE SHOOTING.

What is the name of the drill that is used

The name of the drill that is used is broach cutter.

What is the definition of ballistic

The study or science of a projectile in motion. The flight path includes its travel through the barrel, its flight through the air, and its passage through its target

What type of microscope is used to compare a bullet from the crime scene to the known, test fired bullet from the suspect's weapon? How is the comparison made?

They use the comparison microscope. The way the comparison is made is the firearms examiner takes suspect bullet and the reference sample that he fired from the suspect weapon and compares them side by side.

Before examining individual characteristics like striations, what more general, class characteristic would the firearms examiner look at first to either rule out the known, suspect's weapon or continue looking further

They will first look into class characteristics because it allows a firearms examiner to know whether a bullet was fired from a s&w or a colt, but not a specific s&w or specific colt

Explain how the process of drilling and rifling a gun a barrel makes it unique

This drill leaves microscopic marks left behind on the inside of the gun barrel. The marks are randomly irregular and make each and every gun barrel unique. What makes Rifling a gun barrel unique is when a gun barrel is drilled, the manufacturer must impress the inner surface of the gun barrel, called the "bore" with spiral grooves.

What does a firearms examiner use to test fire a suspect's weapon at the lab? Why? What two things is he/she concerned about when test firing the weapon

Usually, a larger water tank is used into which sample bullet is fired. Because the water tank safely contains the bullet and does not damage it because the bullet doesn't strike any object. The two things is he/she concerned about when test firing the weapon is the lands and grooves of both bullets must have the same width and the striations on each bullet must precisely coincide

• WHAT IS ALGOR MORTIS? AT WHAT RATE DOES IT OCCUR? OF WHAT CONCERN IS IT TO A SUSPICIOUS DEATH INVESTIGATION?

WHILE ALIVE, OUR BODY TEMPERATURE IS APPROXIMATELY 98.6 DEGREES F. WHEN WE DIE, THE BODY BEGINS TO COOL UNTIL IT REACHES THE AMBIENT (SURROUNDING) TEMPERATURE......12-18 HOURS. THE RATE OF HEAT LOSS IS INFLUENCED BY THE SIZE OF THE BODY, WHERE IT IS, WEATHER CONDITIONS, CLOTHING....

GUNSHOT RESIDUE (GSR) COMES OUT OF THE BARREL OF THE GUN WHEN FIRED. ABOUT HOW FAR DOES IT TRAVEL? WHAT CAN WE EXPECT TO SEE ON A VICTIM'S SKIN OR CLOTHING WITH A "CONTACT SHOT"? HOW FAR AWAY IS A CONTACT SHOT? WHAT CAN WE EXPECT TO SEE IF THE GUN WAS 1-2 FEET AWAY? FARTHER THAN 3 FEET AWAY?

We expect to see on victims skin or clothes with a contact shot a heavy concentration of powder burns... Sooty appearance. Loose fibers around hole exhibit scorch marks and star-shaped tear pattern. We expect to see if the gun was 1-2 feet away is a halo effect around the hole and scattered specks of partially burned powder grains without a sooty appearance. In 3 feet away we see little or no powder residue. It can travel to 3-5 feet.

• WHEN COLLECTING A FIREARM AS EVIDENCE FROM A CRIME SCENE, WHAT'S THE BEST WAY TO PICK IT UP? WHAT TWO THINGS ARE WE CONCERNED ABOUT?

We first photography, use gloves and than we pick up by the edge of the trigger guard or the checkered portion of the grip. BE SAFE, and NEVER STICK AN OBJECT INTO THE BARREL OF A GUN TO PICK IT UP. YOU WILL: DISTURB POWDER RESIDUES And ALTER STRIATION MARKS.

• WHAT IS THE NATIONAL INTEGRATED BALLISTICS INFORMATION NETWORK (NIBIN)?

is A SCREENING TOOL. IT PROVIDES A LIST OF POSSIBILITIES THAT MUST BE MANUALLY COMPARED BY A FIREARMS EXAMINER FOR CONCLUSIVE PROOF

• WHAT WAS DONE BEFORE DNA IN AN ATTEMPT TO DETERMINE THE IDENTITY OF THE PERSON WHOSE BLOOD WAS FOUND AT A CRIME SCENE?

Before the DNA we would type the suspect's blood: A=42% B=12% O=43% AB=3%

• WHAT TWO WAYS DO THE POLICE TYPICALLY OBTAIN A DNA SAMPLE FROM A SUSPECT?

Buccal Swab and trained medical personnel take samples if blood

WHAT IS CODIS? WHICH LAW ENFORCEMENT AGENCY MAINTAINS IT? WHAT INFORMATION DOES IT CONTAIN AND HOW DOES THAT INFORMATION GET THERE?

COMBINED DNA INDEX SYSTEM DATABASE DEVELOPED BY THE FBI THAT MAINTAINS NATIONAL, STATE & LOCAL DNA PROFILES FROM CONVICTED OFFENDERS, UNSOLVED CRIME SCENE EVIDENCE, PROFILES OF MISSING PEOPLE

• TRANSFER STAINS

CREATED WHEN A WET, BLOODY SURFACE COMES INTO CONTACT WITH A SECONDARY SURFACE...LIKE SOMEONE STEPPING IN WET BLOOD AND LEAVING A BLOODY BOOT PRINT BEHIND

• PROJECTED STAINS...LOW, MEDIUM AND HIGH VELOCITY (WHAT DOES EACH ONE LOOK LIKE?)

CREATED WHEN AN EXPOSED BLOOD SOURCE IS SUBJECTED TO AN ACTION OR FORCE GREATER THAN THE FORCE OF GRAVITY....THE SIZE, SHAPE AND NUMBER OF BLOODSTAINS WILL DEPEND UPON THE AMOUNT OF FORCE USED...LIKE BEING STRUCK WITH A BASEBALL BAT. LOW VELOCITY...FORCE UP TO 5FT PER SECOND...RELATIVELY LARGE STAINS...4MM IN SIZE OR GREATER. MEDIUM VELOCITY....FORCE FROM 5FT TO 25FT PER SECOND....1 TO 4MM IN SIZE. HIGH VELOCITY...100FT PER SECOND OR GREATER.......1MM IN SIZE OR SMALLER...LOOKS LIKE "MIST"

What is the definition of firearms identification

Concerns itself with determining whether a particular bullet or cartridge was fired by a particular weapon

• PASSIVE STAINS

DROPS CREATED OR FORMED BY THE ACT OF GRAVITY ALONE...LIKE A DROP OF BLOOD DRIPPING OFF THE BLADE OF A KNIFE ONTO THE FLOOR

What is touch DNA

EVIDENCE WITH NO VISIBLE STAINING THAT WOULD LIKELY CONTAIN DNA RESULTING FROM THE TRANSFER OF SKIN CELLS TO AN OBJECT

• DO IDENTICAL TWINS HAVE DIFFERENT DNA?

FOR MANY YEARS, IT WAS THOUGHT THAT EVERYONE HAD UNIQUE DNA EXCEPT FOR IDENTICAL TWINS BECAUSE THEY SHARE THE SAME GENETIC CODE. SCIENTISTS ARE NOW DISCOVERING METHODS TO DIFFERENTIATE BETWEEN THE DNA OF IDENTICAL TWINS

• WHAT IS DNA? WE KNOW IT STANDS FOR DEOXYRIBONUCLEIC ACID, BUT WHAT IS IT?

GENETIC MATERIAL THAT GOVERNS: HAIR COLOR, EYE COLOR, STATURE, BONE DENSITY,n MANY OTHER TRAITS...IT WHAT MAKES YOU....YOU

What is meant by rifling a gun barrel? Why is it necessary?

Just like when a quarterback throws a nice, straight spiral pass to his receiver, the spiral grooves in the gun barrel allow the bullet to travel in a straight path to his its target. It is necessary because This gives the bullet stability so it travels on a true direction.

What are Lands and what are grooves

Lands are the raised portion between the spiral grooves. The grooves are the cut, or low-lying portion of the inner barrel (bore) between the lands.

• WHAT ARE "SHORT TANDEM REPEATS" OR STR'S?

MODERN DNA TYPING USES STR'S. THEY ARE REGIONS OF DNA THAT ARE HIGHLY VARIABLE, BUT ARE PATTERNED IN "SHORT" REPEATING SEQUENCES

• WHAT DOES THE CSI HOPE TO LEARN FROM FORENSIC ENTOMOLOGY, AND WHAT IS THE MOST COMMON, AND THE FIRST INSECT TO ARRIVE TO A DEAD BODY?

MOST COMMON...AND FIRST TO ARRIVE IS THE BLOWFLY BLOWFLY EGGS ARE LAID IN HUMAN REMAINS AND HATCH INTO MAGGOTS ESTIMATE TIME OF DEATH BY EXAMINING THE STAGE OF DEVELOPMENT OF FLY LARVAE..CALLED THE POSTMORTEM INTERVAL OR PMI

• IS IT ALRIGHT FOR A CSI TO MOVE THE BODY BEFORE THE ARRIVAL OF THE MEDICAL EXAMINER?

NEVER MOVE THE BODY BEFORE THE ARRIVAL OF THE M.E

• WHEN SHOULD A CSI HAVE THE MEDICAL EXAMINER RESPOND TO A CRIME SCENE? WHAT MUST BE DONE FIRST?

NOT DONE UNTIL ALL PHOTOGRAPHS, MEASUREMENTS, SKETCHES OF THE BODY HAVE BEEN COMPLETED TIMELY MANNER, HOWEVER

• WHAT IS NUCLEAR DNA AND MITOCHONDRIAL DNA?

NUCLEAR DNA REFERS TO DNA FOUND WITHIN THE NUCLEUS OF THE CELL and MITOCHONDRIAL DNA REFERS TO DNA FOUND OUTSIDE THE NUCLEUS OF THE CELL

• WHEN DID WE FIRST BEGIN TO USE DNA AS A MEANS OF PERSONAL IDENTIFICATION?

1984-1990

• WHAT SHAPE WILL A BLOOD DROP BE IF IT LANDS FROM A 90-DEGREE ANGLE? HOW ABOUT A 45-DEGREE ANGLE?

A 90-DEGREE ANGLE, THE SHAPE OF THE STAIN IS ROUND..THE LENGTH AND WIDTH OF THE STAIN WILL BE EQUAL. AS THE ANGLE DECREASES, THE STAIN BECOMES MORE ELONGATED

• WHY DO WE ALWAYS USE THE PCR METHOD FIRST, EVEN WHEN WE ARE PLANNING TO USE THE RFLP METHOD?

However, we always use PCR first on Crime Scene evidence to have samples available for the Defense Attorney to conduct his/her own testing

• A BULLET AT A CRIME SCENE IS LODGED IN A WALL. WHAT DO WE DO?

IF A BULLET IS LODGED IN A WALL OR OBJECT, PHOTOGRAPH IT, THEN COLLECT THE OBJECT ITSELF (IF MOVABLE EVIDENCE) OR CUT AWAY A SECTION (IF IMMOVABLE). DON'T DIG THE BULLET OUT...YOU WILL SCRATCH IT AND ALTER THE STRIATIONS

• WHAT ARE THE CIRCUMSTANCES FOR A MEDICAL EXAMINER TO GET INVOLVED IN A DEATH?

INVESTIGATES THE CAUSE, MANNER AND TIME OF DEATH WHEN A DEATH IS SUSPICIOUS OR UNEXPLAINED

• TRAIL PATTERN

IS A SERIES OF DROPS FORMED BY BLOOD DRIPPING OFF AN OBJECT OR OFF A PERSON AS THEY MOVE THROUGH THE CRIME SCENE

• VOID PATTERN

IS CREATED WHEN AN OBJECT (SOMETIMES ANOTHER PERSON/SUSPECT) BLOCKS THE BLOOD FROM HITTING A SURFACE (LIKE A WALL)

• AFTER WHAT LENGTH OF TIME CAN WE DETECT BLOOD THAT IS NO LONGER VISIBLE TO THE NAKED EYE?

IT CAN DETECT BLOODSTAINS THAT HAVE BEEN DILUTED UP TO 300,000 TIMES!

• HOW DOES DNA WORK FOR BOTH THE PROSECUTION AND THE DEFENSE?

IT WORKS FOR THE DEFENSE AND TO EXONERATE INNOCENT PEOPLE

• WHAT IS PETECHIA? HOW IS IT CAUSED? WHAT MIGHT IT TELL THE POLICE?

ITS PRESENCE OFTEN MEANS A PERSON WAS STRANGLED, SMOTHERED OR HANGED. THIS DOES NOT NECESSARILY MEAN HOMICIDE. BLOOD LEAKS FROM THE TINY CAPILLARIES IN THE EYES WHICH CAN RUPTURE DUE TO INCREASED PRESSURE ON THE VEINS IN THE NECK/HEAD

• WHAT ARE THE DIFFERENCES BETWEEN THE TWO TYPES OF DNA TYPING?

PCR TESTS ARE SENSITIVE TO CONTAMINATING THE DNA. PROPER HANDLING AND CONTROLS MUST BE IN PLACE AT THE LAB OR THE RESULTS OF PCR ANALYSIS CAN BE INFLUENCED

• MOST POLICE DEPARTMENTS DO NOT HAVE OFFICERS TRAINED TO ANALYZE BLOOD SPATTTER AT A CRIME SCENE. WHAT SHOULD WE, AS CSI'S DO, WHEN WE HAVE A CRIME SCENE WITH SIGNIFICANT BLOOD SPATTER

PHOTOS & ACCURATE DOCUMENTATION SHOW THE PATTERN AND THEIR LOCATION. THEY ALSO DOCUMENT THE STAINS FROM WHICH SAMPLES WERE TAKEN THAT WILL BE / WERE SENT TO THE CRIME LAB. JUST LIKE YOUR CRIME SCENE PHOTOS, YOU NEED TO TAKE OVERALL, MID-RANGE AND CLOSE-UPS OF THE BLOODSTAIN PATTERNS. OVERALLS SHOW THE PATTERN & ITS RELATIONSHIP TO THE CRIME SCENE. MID-RANGE SHOW THE RELATIONSHIP BETWEEN INDIVIDUAL STAINS WITHIN THE PATTERN. CLOSE-UPS SHOW THE DIMENSIONS OF EACH STAIN (TAKEN WITH AND WITHOUT A RULER)

• WHAT IS RIGOR MORTIS? GENERALLY SPEAKING, WHEN DOES IT BEGIN, PEAK AND END? OF WHAT CONCERN IS IT TO A SUSPICIOUS DEATH INVESTIGATION?

RIGHT AFTER DEATH, THE MUSCLES INITIALLY RELAX, THEN GRADUALLY BECOME RIGID DEPENDING UPON CONDITIONS, IT SETS IN AFTER 2-4 HOURS. IT CAN TAKE 8-12 HOURS FOR A BODY TO BE IN "FULL RIGOR" THEN RIGOR MORTIS LEAVES THE BODY AFTER APPROXIMATELY 24 HOURS. Rigor Mortis affects facial muscles first as well as small muscles before it spreads to other parts of the body. Depending on the stage of rigor mortis, the medical examiner may estimate the length of time the victim has been deceased. Absent - person is dead but rigor, although begun, does not show outward signs Minimal - body begins to show signs of rigidity Moderate - obvious signs present

• IN PCR TYPING, WHAT IS THE INSTRUMENT USED TO REPLICATE STRANDS OF DNA CALLED?

SCIENTISTS USE AN INSTRUMENT CALLED A DNA THERMAL CYCLER. IT CAN REPLICATE (COPY) DNA STRANDS MILLIONS OF TIMES IN A MATTER OF HOURS

• SOME DNA SEQUENCES ENCODE IMPORTANT INFORMATION FOR THE CELLS, SOME DO NOT. WHAT IS EACH ONE CALLED?

SEQUENCES THAT CODE ARE CALLED "CODING DNA", SEQUENCES THAT DO NOT, USED TO BE CALLED "JUNK DNA" BUT ARE NOW CALLED "NON-CODING" DNA

• IF A DROP OF BLOOD HITS A HARD, SMOOTH, NON-POROUS SURFACE...LIKE A GLASS TABLE TOP, WILL IT HAVE MORE OR LESS SPATTER THAN IF IT LANDED ON A BEDSHEET, OR A PIECE OF PAPER?

SO A DROP OF BLOOD THAT LANDS ON A GLASS TABLE WILL HAVE LESS SPATTER THAN A DROP OF BLOOD THAT LANDS ON A PIECE OF PAPER WHEN DROPPED FROM THE SAME HEIGHT

• WHAT'S THE DIFFERENCE BETWEEN AN INCISE WOUND AND A STAB WOUND? -

STAB WOUND - DEEPER THAN IT IS LONG and INCISE WOUND - LONGER THAN IT IS DEEP

What are some of the differences between a revolver and a semi-automatic firearm?t

Sometimes rifling methods impart 5 lands and grooves that spiral the bullet to the right, like a .32 s&w revolver. Or rifling might impart 6 lands and grooves that spiral the bullet to the left like .32 colt revolver.

• WHAT TEST CAN BE USED TO SEE IF TRACES OF BLOOD ARE PRESENT IN AN AREA WHERE WE SUSPECT BLOOD HAS BEEN, BUT IT HAS BEEN CLEANED AND WE CAN NO LONGER SEE IT WITH THE NAKED EYE? WHAT TYPE OF REACTION DO WE SEE IF BLOOD IS DETECTED? NAME ONE SUCH PRODUCT THAT IS USED. HOW IS IT USED AT A CRIME SCENE?

THE 2ND TYPE OF PRESUMPTIVE TESTS ARE THOSE THAT CAUSE A GLOWING REACTION IN THE PRESENCE OF BLOOD AS OPPOSED TO A COLOR CHANGE. THE CHEMICAL REACTION CAUSES THE BLOOD TO FLUORESCE UNDER A UV LIGHT SOURCE. IT IS GREAT TO UNCOVER BLOODSTAINS INVISIBLE TO THE NAKED EYE. ONE OF THE BEST FLUORESCENT CHEMICA PRESUMPTIVE TESTS FOR BLOOD IS LUMINOL. LUMINOL IS A HIGHLY SENSITIVE CHEMICAL THAT REACTS WITH BLOOD AND ACTUALLY EMITS LIGHT WHEN BLOOD IS PRESENT. LUMINOL IS ABLE TO EXPOSE BLOOD IN PLACES THAT HAVE BEEN CLEANED REPEATEDLY, UNLESS BLEACH WAS USED. IT CAN DETECT BLOODSTAINS THAT HAVE BEEN DILUTED UP TO 300,000 TIMES! LUMINOL IS SPRAYED ON THE SURFACE WHERE THE SUSPECTED BLOODSTAIN IS PRESENT. THE LIGHTS ARE DIMMED, AND A UV LIGHT IS PASSED OVER THE AREA. THE CSI CAN OBSERVE THE BLOOD GLOW, OR LUMINESCE.....THUS ITS NAME....LUMINOL

• WHAT DO WE MEAN BY THE "CAUSE OF DEATH"? WHAT ARE SOME OF THE DIFFERENT CAUSES OF DEATH?

THE CAUSE OF DEATH IS THE INJURY OR DISEASE THAT LED TO THE PERSON'S DEATH Drug related, direct cause, causes complications to contribute to death. Blunt-force trauma, sharp-force injury, stab wound, incise wound.

Shotguns often shoot what we call "shot".... Pellets that exit the barrel in one mass but spread over distance. How can we determine how far away the shooter was from the target

THE DISTANCE BETWEEN A FIREARM AND ITS TARGET CAN SOMETIMES BE DETERMINED BY THE ANALYSIS OF THE DISTRIBUTION OF GUNPOWDER RESIDUE, ITS PATTERN OR ITS SPREAD ON THE TARGET (LIKE A PERSON). THIS IS IMPORTANT IN A SELF-DEFENSE CLAIM BECAUSE INVESTIGATORS CAN DETERMINE HOW FAR AWAY A VICTIM AND SUSPECT WERE FROM ONE ANOTHER WHEN THE SHOOTING OCCURRED. IT IS ONLY ACCURATE WHEN THE FIREARMS EXAMINER HAS IN HIS/HER POSSESSION THE SUSPECT WEAPON AND KNOWS THE TYPE OF AMMUNITION THAT WAS USED. OTHERWISE, IT CAN ONLY BE STATED THAT A SHOT COULD HAVE BEEN FIRED FROM A CERTAIN DISTANCE..IT IS ONLY AN Approximation

• WHAT DO WE MEAN BY THE "MANNER OF DEATH"? WHAT ARE SOME OF THE MORE COMMON MANNERS OF DEATH WE SEE IN A SUSPICIOUS OR UNEXPLAINED DEATH?

THE MANNER OF DEATH IS A DETERMINATION MADE BY A FORENSIC PATHOLOGIST OF THE CAUSE OF DEATH. Homicide. Suicide

• WHAT ARE THE VARIOUS ROLES A MEDICAL EXAMINER HAS, AND WHAT IS HIS/HER PRIMARY ROLE?

THE MEDICAL EXAMINER PERFORMS VARIOUS ROLES: WHO IS THE VICTIM?, WHAT INJURIES ARE PRESENT?, WHEN DID THE INJURIES OCCUR?, HOW WERE THE INJURIES MADE?, WHICH WERE FATAL?. BUT THE PRIMARY ROLE OF THE MEDICAL EXAMINER IS TO DETERMINE THE CAUSE, THE MANNER AND THE APPROXIMATE TIME OF DEATH....IF POSSIBLE

• WHAT IS THE NAME OF THE TEST THAT THE LAB PERFORMS TO DETERMINE WHETHER BLOOD FROM THE CRIME SCENE IS HUMAN OR ANIMAL? WHAT DOES THIS TEST INVOLVE?

THE NAME OF THE TEST THAT THE LAB PERFORMS TO DETERMINE WHETHER BLOOD FROM THE CRIME SCENE IS HUMAN OR ANIMAL is precipitin test. THE PRECIPITIN TEST INVOLVES INTRODUCING HUMAN BLOOD TO ANIMAL BLOOD. THE BLOOD OF HUMANS AND ANIMALS CONTAIN DIFFERENT PROTEINS, AND BLOOD FROM ANIMALS WILL NOT ACCEPT PROTEINS FROM HUMAN BEINGS.

• HOW MAY WE DETERMINE THE POINT OF ORIGIN....THE SPOT WHERE THE VICTIM WAS ASSAULTED BY LOOKING AT A BLOOD SPATTER PATTERN ON A WALL?

THE ORIGIN MAY BE ESTABLISHED BY DRAWING STRAIGHT LINES FROM VARIOUS BLOODSTAINS TO SEE AT WHAT POINT THE LINES CONVERGE. THE LINES ARE DRAWN FROM THE ROUND PART OF THE STAIN...NOT THE TAIL BECAUSE YOU ARE LOOKING FOR THE DIRECTION FROM WHICH THEY CAME..NOT THE DIRECTION IN WHICH THEY ARE GOING. THE POINT WHERE THE STRAIGHT LINES ALL CONVERGE REPRESENTS THE POINT FROM WHICH THE BLOOD CAME FROM

How does a fired bullet posses individual characteristics

THE RANDOM DISTRIBUTION OF THESE MARKINGS AND THEIR INDIVIDUAL IRREGULARITIES ARE IMPOSSIBLE TO DUPLICATE. NO TWO RIFLED BARRELS....EVEN THOSE MANUFACTURED IN SUCCESSION BY THE SAME COMPANY...HAVE IDENTICAL STRIATION MARKS. IT IS THE UNIQUE STRIATIONS THAT GIVE INDIVIDUAL CHARACTERISTICS TO THE BARREL OF EVERY GUN.

• HOW MAY WE DETERMINE THE DIRECTION THAT BLOOD DROPS ARE TRAVELING?

THE SECOND GENERAL RULE IS THAT THE DIRECTION THAT THE BLOOD IS TRAVELING WHEN IT HITS AN OBJECT CAN BE DETERMINED BY ITS SHAPE. THE POINTY END OF THE BLOODSTAIN ALWAYS FACES ITS DIRECTION OF TRAVEL. SO, WHEN YOU HAVE A ROUND BLOODSTAIN ON A WALL WITH A "TAIL" THAT POINTS TO THE RIGHT....THE BLOOD WAS TRAVELING FROM THE LEFT TO THE RIGHT

• WHAT IS THE TEST CALLED THAT A CSI CAN USE AT A CRIME SCENE TO DETERMINE WHETHER A SPOT OR A STAIN IS BLOOD? WHAT IS THE NAME OF ONE OF THESE TESTS AND EXPLAIN HOW IT IS USED? WHAT TYPE OF REACTION WOULD WE SEE IF IT TESTS POSITIVE FOR BLOOD?

THE TEST CALLED THAT A CSI CAN USE AT A CRIME SCENE TO DETERMINE WHETHER A SPOT OR A STAIN IS BLOOD is Presumptive test. The name of one of these is called Color test. THESE TESTS ALL INVOLVE INTRODUCING CERTAIN CHEMICALS TO THE SUSPECTED BLOOD. IF BLOOD IS IN FACT PRESENT, A CHEMICAL REACTION WILL OCCUR WITH THE HEMOGLOBIN IN THE BLOOD. If the result is positive the reaction will see is blue color.

• WHAT IS LIVOR MORTIS? HOW LONG DOES IT TAKE, GENERALLY SPEAKING, TO SET IN? WHAT DO WE SEE? WHAT MIGHT IT TELL A CSI IN ADDITION TO THE APPROXIMATE TIME OF DEATH?

While alive, the heart pumps blood to all parts of the body, This stops after death, What happens to the 1.25 - 1.5 gallons of blood in our bodies? THE SKIN TAKES ON A PURPLISH COLOR IN THESE AREAS. IT STARTS IMMEDIATELY AFTER THE HEART STOPS AND THE BLOOD CONTINUES TO SETTLE FOR APPROXIMATELY 12 HOURS. WE SEE SIGNS OF IT AFTER ONLY A COUPLE OF HOURS. THE SKIN WILL NOT BE DISCOLORED IN AREAS WHERE THE BODY IS PRESSED AGAINST THE GROUND OR FLOOR, OR IN AREAS WHERE THERE ARE RESTRICTIVE CLOTHING. THE BLOOD CANNOT SETTLE IN THESE AREAS BECAUSE OF THE PRESSURE.

If we never recover the firearm used in a crime, but we do recover the bullet(s) perhaps at an autopsy, can the lab still provide useful information? What?

Yes they can because have both class and individual characteristics. If we recover the bullet and the firearm, we can send both to the Lab and ask the Lab if that gun fired the fatal bullet. If we recover the bullet but not the firearm (like what happened in the Aaron Hernandez case) the Lab can still give us useful information. They can tell us the caliber of the murder weapon, like a 9mm or a .45. They can also look at the number of lands and grooves and whether the spiraling goes to the left or right. This can tell us the manufacturer. So from the bullet alone, the Lab could tell us that the murder weapon we are looking for is a .45 Smith & Wesson.