Term 1 Forensics Study Guide

What is the goal of forensics?

using scientific knowledge and techniques to help with a criminal investigation, especially in trial

What is the proper method of transporting a microscope?

carry the microscope by the arm and the base

Which objective lens should you never use in conjunction with the course adjustment knob?

40X high objective lens because it can cause damage to the slides.

When using a microscope, how will we see a specimen? Will we see it just as it was placed under the microscope?

No. used to magnify objects that are too small to be seen with the naked eye. See structures of the specimen

What is deductive reasoning?

deriving the consequences from facts using a series of logical steps

How do people process information/stimuli that bombards them on a daily basis?

Information from our senses

What we pay attention to

Perception

Short-term memory

Long term memory

What is the problem with trusting eyewitnesses at a crime scene?

Eyewitnesses can be influenced by stress, trauma, or misinterpretation of events, leading to inaccuracies in their accounts. Additionally, memory can be unreliable and subject to distortion over time.

How can we, as forensic scientists, become better observers?

rely on their ability to observe, interpret, and report observations clearly

What is the purpose of the innocence project?

to reexamine post-conviction cases and exonerate those that are wrongfully convicted

What piece of evidence does the innocence project use to help set innocent people free?

DNA testing and analysis

What percentage of wrongful conviction cases has the Innocence Project help solve?

87%

Why is the Chain of Custody important to follow?

It ensures that evidence is preserved, unaltered, and can be reliably linked to the investigation.

What are the 7 S’s of crime scene investigation?

Securing the Scene

Seperating the Witnesses

Scanning the Scene

Seeing the Scene

Sketching the Scene

Searching the Scene

Securing and Collecting Evidence

How is wet evidence collected?

placed in a brown bag and taken to the crime lab to be allowed to air dry. While drying, white paper is placed under the items to collect any trace evidence that falls. This evidence is processed separately.

How is small, dry evidence collected?

placed in a bindle, also known as a druggiest fold

If someone receives bagged evidence with a signature on a label, how must they go about opening the bag to get to the evidence?

will enter the bag through the bottom (by cutting it). Cannot break the seal of the evidence tape

What happens when a first responder “secures a crime scene?”

set clear boundaries around a crime scene area to protect evidence

secure if injured or suspect is there

log who’s in and out

What is the difference between circumstantial evidence and direct evidence?

Direct: includes firsthand observations (eyewitness accounts, police dashboard, video surveillance, voice recordings, signed ransom notes, reports)

Circumstantial: Indirect suggestion that can be used to IMPLY a fact, but not directly prove it, physical or biological (prints, DNA, ballistic evidence, fibers, hair)

Fingerprint left on a door handle of a car (Circumstantial or Direct)

Circumstantial physical

A written confession signed by a suspect (Circumstantial or Direct)

Direct

A piece of gum left at a crime scene (Circumstantial or Direct)

Circumstantial physical

A tape recording of a suspect admitting to a crime (Circumstantial or Direct)

Direct

What is a bindle?

A small, folded or wrapped package used to contain and preserve evidence, often seen in drug-related cases.

What is the difference between individual evidence and class evidence?

Individual: narrows to one individual (DNA, Hair w follicle, fingerprints)

Class: narrows to a group of people/items (shoe prints, blood type, hair w/o follicle)

Skin cells found under the fingernails of a victim (DNA), (Class or Individual)

Individual

Size 9 Nike shoe found beside a dead body (Individual or class)

Class

1990 Ford Explorer seen driving away from an armed robbery ( class or individual)

class

A fingerprint left on a soda can found at a crime scene (Class or Individual)

Individual

What is the difference between physical evidence and biological evidence?

Physical: all prints, bullets, weapons, synthetic fibers-plastics

Biological (come from living things) DNA, hair, natural fibers-cotton

Jacket fiber (100% cotton) (Physical or biological)

biological

Bullet casing 

physical

Glass fragments

physical

Ransom note

physical

What is the method by which a photographer takes photographs at a crime scene?

use an item of scale

each piece of evidence must be photographed at 3 different angles

each angle should be photographed at 3 distances - 9 photos minimum

What must be included in a crime scene sketch?

Location (address, room, area, etc.)

Date

Name of person who drew the sketch

indicate with arrow and the letter “N", true north

Measurements

Legend

Scale

Type of Crime

Case Number

Victim’s name (if known and applicable)

Other officers names (if applicable and relevant)

What does Locard’s Principle of Exchange state?

states when a person comes into contact with an object (or another person), a cross-transfer of physical evidence can occur

*the intensity, duration, and nature pf the entities in contact determine the extent of the transfer

*forensics is built upon this principle

What is the importance of the Frye Standard?

Originated with Frye vs. United States (lie detector admissibility)

States that evidence must be accepted by the scientific community before its admitted to the court

*relates to evidence

*allows judge to admit evidence

What is the importance of the Daubert principle?

originated in 1993 (Daubert Vs. Merrel Dow Pharmaceuticals)

a ruling that allows the trial judges to make this ultimate decision regarding expert testimony

*relates to expert witness

*allows judge to admit expert witnesses

How has forensics changed over time?

Forensics has evolved significantly with advancements in technology, including the use of DNA analysis, digital forensics, and improved crime scene investigation techniques. These developments have enhanced the accuracy and reliability of evidence, leading to more effective criminal investigations and prosecutions.

What are the first 10 amendments to the US constitution called?

Bill of Rights

What does Article 6 in the Bill of Rights ensure citizens of?

ensures that a person will be tried by an impartial jury of his or her peers

What 3 tests can be used to detect alcohol in the system?

Breath Test (Breathalyzer), Blood, Urine

The cooling of the body after death is known as…….

algor mortis.

The immediate reason for a person’s death is known as….

the cause of death.

What is the “forensic” definition for death?

cessation, or end, of life

The process of rotting and breaking down is known as…..

Decomposition

The study of insects is known as….

entomology.

A _________ is a doctor that performs autopsies on the human body

pathologist

What is the first step of an autopsy?

External autopsy

what is the final step of an internal autopsy?

Returning all organs and carefully suturing the body

If a maggot is found with 2 spiracle slits near the an, it is most likely in this stage of its life cycle?

Instar 2

What is the first stage of the life cycle of a blow fly?

egg stage

2mm

white

found in warm, moist places (mouth, ears, eyes)

Before a blow fly hatches into an adult, is is at what stage in the lifecycle process?

Pupa

The stiffening of the skeletal muscles after death is known as…..

rigor mortis.

How many hours after death does lividity begin to set in?

2 hours

How many hours does it take for lividity to become permanent?

8

The pooling of blood in tissues after death is known as….

lividity

What are the 4 manners of death?

Natural, Accident, Suicide, Homicide

If a person died of a self-inflicted gunshot wound, what manner of death will be listed on their death certificate?

Suicide

If a person dies of old age, what manner of death will be listed on their death certificate?

Natural

If a person is murdered, what manner of death will be listed on their death certificate?

Homicide

If a person dies in a car accident, what manner of death will be listed on their death certificate?

Accidental

What does it mean if lividity is present on the opposite side from which the victim is laying/sitting?

It indicates that the body has been moved after death

Where does rigor begin to set in first?

Face and hands

If a dead body exhibits rigor all over its body, how long has it been dead?

12 hours

The environmental condition that affects TOD calculations is known as ____________ temperature.

ambient

What does heat do to the process of livor/rigor mortis?

Heat speeds up the process

What happens to the body temperature of a person within the first hour of death?

Maintains its temperature before beginning to cool.