CSI FINAL

what is forensic science?

the application of science to the criminal and civil laws that are enforced by police agencies in a criminal justice system

what two things does forensic investigation require?

1. development of the principles and techniques to identify and compare physical evidence

2. combining these principles in a manner that can be practically applied in a criminal justice system

human identification and fingerprints were first recognized by ?

the chinese

who was Marcello Malpighi and what did he do in terms of human identification and fingerprints?

he was a professor of anatomy at the university of bologna, italy and he first recorded notes regarding ridges, spirals, and loops in fingerprints in 1686

who suggested that fingerprints could be used in human identification?

Thomas Taylor in the late 1800s, and later Henry Faulds

who provided statistical evidence for the uniqueness of fingerprints?

Francis Galton and his book “Fingerprints”

who created the procedure of anthropometry?

Alphonse Bertillon

what is anthropometry?

procedure that involved taking a series of bodily measurements as a means of distinguishing one individual from another

who was Hans Gross and what did his book on criminal investigation discuss?

he was an austrian public prosecutor and his book discussed how microscopy, chemistry, physics, mineralogy, zoology, botany, anthropometry, and fingerprinting could be used to assist in forensic investigations

what did Carl Wilhelm Scheele do in 1775?

he was the first to detect arsenic in corpses

what did Valentin Ross do in 1806?

discovered a precise method of detecting small amounts of arsenic in a victim’s stomach

who was the father of forensic toxicology?

Mathieu Orfila

what did Mathieu Orfila do in 1814?

published a treatise on the detection of poisons and their effects on animals

what did William Nichol do in 1828?

invented the polarizing microscope

what did Henri-Louis Bayard do in 1839?

formulated the first procedures for microscopic detection of sperm

what did Sir Arthur Conan Doyle do?

created Sherlock Holmes, and was the first to apply the newly developing principles of serology, fingerprinting, firearms identification, and questioned-document examination long before their value was recognized and accepted by real-life criminal investigators

what is serology?

study of blood and bodily fluids

what did Dr. Karl Landsteiner do in 1901?

discovered blood types A, B, AB, and O

what is Locard’s exchange principle?

states that when a criminal comes in contact with an object or person, a cross-transfer of evidence occurs

what did Dr. Walter C. McCrone do in terms of microscopy?

applied microscopy to analytical problems including forensics

what did U.S. Army Colonel Calvin Goddard do?

refined firearms examination using comparative microscopic analysis of crime scene bullets versus test fired bullets to see if the bullets could have been fired from the same gun

who developed the first DNA profiling test and what did they use it for?

Sir Alec Jeffreys in 1984, and two years later used it to identify Colin Pitchfork as the murderer of two young English girls

who did NOT contribute to forensic toxicology?

Alphonse Bertillon

what is the oldest forensic laboratory in the United States?

Los Angeles Police Department, created in 1923

what is the world’s largest forensic laboratory?

the FBI Laboratory

what are the four major federal crime laboratories?

1. FBI Laboratory in Quantico

2. Drug Enforcement Administration (DEA) laboratories

3. laboratories of the Bureau of Alcohol, Tobacco, Firearms, and Explosives

4. U.S. Postal Inspection Service laboratories

what three government-funded institutes provide forensic services in Canada?

1. three RCMP regional laboratories across Canada (Ottawa, Vancouver, and Edmonton)

2. the Centre of Forensic Services (CFS) in Toronto (also the Northern Regional Laboratory of Forensic Sciences in Sault Ste. Marie)

3. the Institute of Legal Medicine and Police Science in Montreal

how many OPP forensic identification laboratories are in Ontario?

thirteen

what are 5 basic services of the USA crime lab?

1. physical science unit

2. biology unit

3. firearms unit

4. documentation examination unit

5. photography unit

what happens in the physical science unit?

they use techniques of chemistry, physics, and geology to examine drugs, glass, paint, explosives, and soil

what happens in the biology unit?

they use DNA profiling and bodily fluid analysis as well as hair, fibres, and botanical material (e.g. wood and plants)

what happens in the firearms unit?

they examine firearms, ammunition of all types, discharge residue, and tool marks

what happens in the documentation examination unit?

they examine handwriting and typewriting, document source and authenticity, paper ink, and indent writing

what happens in the photography unit?

they use regular and highly specialized photographic techniques using UV and X-rays to make the invisible visible

what are four optional services in the USA crime lab?

1. latent fingerprint unit

2. polygraph unit

3. voiceprint analysis unit

4. crime scene investigation unit

what are seven specialized services offered in USA crime labs?

1. forensic pathology

2. forensic anthropology

3. forensic entomology

4. forensic psychiatry

5. forensic odontology

6. forensic engineering

7. forensic computer and digital analysis

what are the four CFS forensic units?

1. biology

2. chemistry

3. physical sciences

4. toxicology

what are the five steps of the scientific method, as presented in the textbook?

1. formulate a question worthy of investigation

2. formulate a reasonable hypothesis to answer the question

3. test the hypothesis through experimentation

4. “upon ‘validation’ of the hypothesis, it becomes suitable as scientific evidence”

5. think “failure to reject”

what does Frye v. United States state?

that it rejects the scientific validity of the lie detector and established that “in order to be admitted as evidence at a trial, the questioned procedure, technique or principle must be “generally accepted” by a meaningful segment of the relevant scientific community "

a witness may offer expert testimony on scientific or technical matter in what three cases?

1. testimony is based upon sufficient facts or data

2. testimony is the product of reliable principles and methods

3. witness has applied the principles and methods reliably to the facts of the case

once it is established that a crime is not in progress, the first responding officer to a crime scene is responsible for what four things?

1. acquiring medical assistance for injured victims

2. detaining any potential suspects or witnesses

3. securing the crime scene to the greatest extent possible

4. calling for any additional personnel needs such as other officers and/or forensic investigators

the walkthrough or initial survey of the crime scene includes what four things?

1. locating the perpetrator’s point of entry and exit

2. taking an indirect path to the centre of the crime scene

3. locating and documenting obvious items of evidence

4. observing and recording the conditions of the crime scene

what is the primary crime scene?

the location at which the initial crime occurred

what is the secondary crime scene?

the location at which events after the initial crime occurred

what is a command centre?

a secure site outside the boundaries of a crime scene where equipment is stored, tasks are assigned, and communication occurs

what four things do investigators do at a command centre?

1. receive their assigned tasks from the lead investigator

2. store their equipment

3. meet to discuss aspects of the crime scene

4. communicate with law enforcement personnel and personnel at other crime scenes

what are the three steps investigators typically take to control access to a crime scene?

1. establish the boundaries of the scene

2. prevent unauthorized access to the crime scene

3. keep an accurate log of everyone who enters or leaves the scene

when locating evidence, the investigator must do what four things?

1. record its location and make notes that provide a detailed description of the evidence

2. sketch the evidence relative to the scene

3. photograph scene shots and close-up

4. mark its location with an evidence marker for collection and processing

what is a strip/line search pattern?

one or two investigators start at the boundary of the crime scene and search in straight lines across to the other side of the crime scene

what is a grid search pattern?

two or more investigators form a grid by searching in line patterns that overlap and are perpendicular to each other

what is a spiral search pattern?

one investigator searches in a spiral path from the centre of the crime scene to the boundary (outward) OR from the boundary of the crime scene to the centre (inward)

what is a wheel/ray search pattern?

several investigators search in straight lines from the centre to the boundary (outward) OR from the boundary to the centre (inward)

what is a quadrant/zone search pattern?

the crime is divided into smaller sections (zones) and one or more investigators are assigned to search each zone

crime scene notes should begin with what four things?

1. identity of the person who contacted the investigator

2. time of contact and arrival at the crime scene

3. preliminary case information

4. personnel present on arrival and those being contacted

photographs taken at a crime scene should show what four things?

1. layout of the crime scene

2. position of collected and uncollected evidence

3. point of view of victims, suspects, and witnesses

4. original condition of items of evidence at the scene

in order to be admissible as evidence within the justice system, photographs must meet what four points of criteria?

1. must represent the crime scene as found, without manipulation or bias

2. any re-creations of scenes or manipulation must be documented

3. must have bearing on the case in question

4. must not engage in emotional manipulation of the jury

what is film speed?

a measure of the light-gathering capacity of the film

how is a digital photograph made?

when a light sensitive microchip captures light on each of the pixels

how many pixels are in a megapixel?

one million

in order to be admissible in the justice system, digital images must meet what four points of criteria?

1. must be reliable

2. must be reproducible

3. must be secured and their integrity must be assured

4. both original and altered images and their metadata must be made available within the judicial process

what are the two most commonly used cameras at crime scenes?

1. single lens reflex (SLR)

2. digital single lens reflex (DSLR)

what is a DSLR camera?

a type of camera that uses the same lens for viewing and for taking the picture

what does a lens do?

bends light to focus an image on the film or digital microchip

what is focal length?

the distance between the lens and the image projected on the film or microchip, which determines the area shown in the resulting photograph

what is a normal lens used for and what is its focal length?

used for most photographs that need to be taken at a crime scene because it can show as much area as half a wall; focal length of 50-55mm

what is a telephoto lens used for and what is its focal length?

used to magnify images; focal length of 100mm or greater

what is a wide-angle lens used for and what is its focal length?

used to show much more area in one photograph than a normal lens; focal less of 35mm

what is a macro lens used for and what is its focal length?

used for highly-detailed, close-up photographs; focal length of less than 50mm

what is a multi-purpose lens used for and what is its focal length?

used to take normal, wide-angle, and telephoto photographs; focal length of 28-80mm

what is aperture?

a measure of the diameter of the opening of the diaphragm, which allows light to reach the film or microchip

what is shutter speed?

the length of time that a film or microchip is exposed to light

what is depth of field?

the amount of area in the foreground and background of an object in focus that is also relatively in focus

what does ISO stand for and what is it?

International Organization for Standardization and it describes the camera’s sensitivity to light

what is colour temperature?

measure of the “degree of whiteness” of a light source compared to a hypothetical source of perfect white light

what are the six basic guidelines of crime scene photography?

1. photograph the crime scene in an unaltered condition

2. fill the frame

3. avoid shadows in the photograph

4. maximize depth of field

5. photograph the scene in a logical sequence

6. keep a log

what are five DSLR modes?

1. auto mode

2. sports mode

3. night mode

4. landscape mode

5. portrait mode

what is f-stop?

a setting on a camera that controls the aperture diameter to determine the amount of light transmitted through the lens to the film or microchip

what is auto mode?

automatically selects an appropriate f-stop and shutter speed for conditions being photographed

what is sports mode?

captures subjects in motion by using a higher (faster) shutter speed

what is night mode?

uses a lower (slower) shutter speed to gather as much light as possible to create the image

what is landscape mode?

automatically selects higher f-stops to improve depth of field

what is portrait mode?

selects lower f-stops to decrease the depth of field and make the subject stand out clearly against a blurred background

what are the two types of camera filters?

1. barrier

2. bypass

what are barrier filters?

filters that block one specific wavelength (colour) of light from reaching the film or microchip, making areas of that colour appear lighter in the photograph

what are bypass filters?

filters that allow only a small range of wavelengths of light to reach the film or microchip and block all others

what are overview photographs?

photographs of the entire scene and surrounding area, including points of exit and entry

what is a visual tag?

an object recorded in multiple overview photographs to help visually piece the scene together

what are medium-range photographs?

photographs that show the layout of smaller significant areas of the crime scene and include at least one photograph of the “centre” of the scene

what are close-up photographs?

photographs that show greater detail of individual objects or evidence and are taken last

what are the four minimum photographs required at a crime scene?

1. overview

2. medium-range

3. close-up

4. close-up with scale

what does night photography require?

the use of external lighting or “painting with light”

what does indoor photography require?

photographs of the neighbourhood, points of entry and exit, and all walls, floors, and ceilings

what does outdoor photography require?

location of photographs to be recorded by a Global Positioning Device or measurements from landmarks

what does arson photography require?

photographs of the point of the fire’s origin and use of special equipment or techniques to provide maximum contrast in photographs of charred area; may also include photographs of crowd outside because arsonists commonly return to the scene

what does sexual assault photography require?

photographs of all wounds and clothing while showing discretion to the victim

what does impression photography require?

oblique lighting to show details and a scale to later create a 1:1 scale photograph for comparison to footwear or tire samples

what does bloodstain photography require?

photographs of all pertinent stains and determined area of convergence or area of origin; bloodstains treated with luminol are treated in complete darkness

what does latent fingerprint photography require?

photographs with a 1:1 scale using a special latent fingerprint camera or a regular camera fitted with an adapter; black and white film used to show greater contrast

what are three advantages of digital crime scene photography?

1. ability to observe images immediately after taking them ensures important photographs are clear and show the best possible detail

2. resolution available can exceed six megapixels, while the maximum resolution offered by a film SLR camera is equivalent to about five megapixels

3. computer programs can stitch digital crime scene images together to create a 3D view of the crime scene

what are two disadvantages of digital crime scene photography?

1. digital images are easily manipulated using computer programs and may not show an accurate depiction of the crime scene

2. digital images may lose image data or details through compression