unit 3 exam

1.Discuss What tool Mark Identification is, than Identify andexplain the thie types of Marks left behind at a crime Scene

Tool Mark identification is When Fs Look at Marks left by tools at a crime score to figure out which tool was used.

Each tool Makes a Unique Mark because of tiny Scratches Or damage on it.

Types

Identation - Made When a tool is pressed into a soften surface

EX) Indentation in to Soap

Abrasioni- Made When a 000/ Stides or Scrapos acioss a

Surface [leaves Scratch Marks)

eX. A crow bar draggad across a doon

Cut Marks - Made When a bool cuts through Something

ex) Wire cutters used on a lock

Explain the purpose of CIBIN

CIBIN stands for Canadian interrogated ballistics, identification network The purpose is to help police and forensic sciences, compared to marks and firearm evidence. It uses a big database of past cases to find matches.

Explain the three types of cast impressions that can be left at a crime

Patent-visible and easy to see made when blood sticks to a shoe and leaves a print example of bloody shoe print on the floor

Latent hidden and can’t be seen without special tools it’s caused by oils/tiny dirt particles. It’s found using dust powder or special lighting

Plastic-3-D print left in soft materials like mud, snow or soap, example shoe print in wet soil

Why are some impressions important to collect at a crime scene?

Show impressions are important because it gives investigators clues about the size type of shoe person height and weight. However, a person walks number number of people have seen and where people move entry/exit points.

What is the difference between wheelbase and track with?

Wheelbase is the distance from the front wheels to the back wheels

Truck quits it’s the distance from centre of one tire to the centre of the tire on the opposite side

How do tire marks show direction and speed?

Skidmarks happen when brakes are slammed links can help estimate speed

Yaw marks curved marks that show the car was turning too fast and lost control

Tire scrubs show where a car hit something they help find point of impact by looking at tire marks it can help investigators find out vehicles movement directions speed during chrome

Know the two ways dental patterns are used in forensics forensic

Number one to identify human remains teeth are strong and last a long time so they can help identify a person when body is damaged or decomposed

To match bite marks, if you suspect or victim leaves a bite mark at scene the pattern is unique

Forensic scientist can use up to 76 points of comp When matching a bite marks to a suspect

Discuss the various factors that make a persons jaw unique

The size of teeth and jaw

Crowding or spacing of teeth

Dental work

Tooth damage

Colouration

Alignment of teeth

Tooth dimension

Arch of roof of mouth

What is the study of fingerprints called and why are they referred to as the silent witnesses?

The study is called dermatologyphics fingerprints are referred to a silent witnesses because they are left behind without saying anything but tell crime scene investigators who was there they don’t change overtime and they are unique to each person

Identify and explain the three types of fingerprints that can be found at a crime scene

Patent- visible happen when finger is covered in blood and touches a surface example bloody fingerprint on glass

Latent - invisible to naked eye happen when sweat/oil left on a surface needs special chemical powders or lighting to be seen

Plastic-3 d prince left and soft materials like wax soap finger leaves actual print in the material

Identify and explain the eight different types of fingerprint patterns

Ulnar loop - loops toward pinky side

Radial loop -loop towards thumb side

Double loop-2 loop swirl together and form an S shape

Plain whorl - circular pattern in centre of print

Central pocket loop- a loop with a whoral in center

Accidental loop- a mix that don’t fit in any group

Plain arch-ridge flow in

Tented arch - like a plain arch, but has a sharp spike

What is the most common type of fingerprint patterns?

Ulnar loop makes up 65% of all fingerprints

Explain the details of minutia points, including the many types

Minutia points are important in forensics because they help identify people by unique features. They are small detail details, where fingerprints ridges, and split or change.

Ridge ending- ridge suddenly stops

Bifabrication- redige splits into two

Ridge dot - tiny dot like ridge

Island - shirt ridge between ridges

Lake - open space between ridges

What is the primary concern of firearm identification?

The primary concern of firearm identification is to find out if a bullet or cottage case was fired from a specific gun. It’s possible because of the wear and tear on guns and imperfection.

Explain what is the purpose of rifling discuss how it can help investigators determine if a certain gun was used at a crime scene

Rifling is a special pattern of raised and lowered grooves inside a gun barrel. Its purpose is to make a bullet spin as it moves through the barrel which keeps the bullet table and accurate. It helps investigators because every gun has a unique rifling pattern. the bullet gets scratched and marked from rifling.

What is meant by the class characteristics of a fired cartridge

When a gun is fired the cartage case shows certain basic features called class characteristics which includes the size shape of firing pen and marks made by gun on the back of the cottage character are tiny, imperfections on part of a firearm

Know why ballistics can help forensics at a crime scene

Ballistics is the study of how bullets and guns work it helps forensic scientist, cause every gun has a unique marks on bullets and cartilage cases. Those marks can be matched to a gun like fingerprints helps figure out which type of gun was used. Ballistics can also figure out the direction distance and speed. The bullet was fired.

Bullet components

It’s made out of lead or brass

Kissing is made out of lead or brass usually

Gunpowder

Timer