Crime Scene Midterm
When should the initial responding officer start considering personal safety when dealing with a call for service?
before scene
total station systems
combines transits, lasers and computer technology
What is the instrument that detects indented writings?
electrostatic detection apparatus
What are the common f-stops/apertures?
f/1.8, f/2.8, f/4/0, f/5.6, f/8.0, f/11, f/16, f/22
triangulation or rectangular coordinates on a grid
good for large scale scenes with multiple teams, grid is made by placing stakes that are then used as landmarks
Which fingerprint pattern type is the most popular at 65% of all pattens?
loop
Which is the least used search pattern?
point to point
In _____________________ a sighting device is used to measure the angular direction of the evidence from the datum point.
polar coordinate
Which range of the electromagnetic spectrum destroys DNA?
shortwave UV
There are two types of evidence in any investigation they are:
testimonial and physical
What are the different types of search patterns according to Gardner? Pick one and describe in depth.
-circle or spiral search -strip and line search -grid search -zone search -point to point search - circle/spiral search is where the searcher begins on the outside area of a room or area and then move slowly inward toward a primary focal point. it is also employed in a reverse manner when a searcher will begin toward the central focal point in an area and move outward - either way, must maintain a pace that allows for full evaluation
According to Gardner, what do officers look at when establishing initial perimeter?
-primary focal points -natural entry and exit points -secondary scenes
What is the least and most used search pattern according to Gardner?
- point to point is rarely used in the US - circle and spiral often used for interior - strip and line search used often exterior
What are the 4 elements of good exposure?
-The intensity of light falling on the scene, known as incident light. -The intensity of light reflected by the scene, known as reflected light. -The sensitivity of your camera's image sensor, known as the ISO value. -The aperture of your lens, known as the f-stop
RUVIS technology
-allows the visualization of latent prints before dusting or development on most nonporous surfaces as well as visualization of other evidence such as latent footwear patterns -primary system includes a UV/C source and imager, two filters are supplied: one clear and one mirrored -since it uses UV/C, it is destructive and can damage DNA or harm the user if not used properly with caution
Glass is a valuable trace evidence item. Generally, labs effort is directed into one of three basic determinations, what are they?
-direction of force -glass type -sequence of force
essential sketch elements
-heading -diagram area -legend -title block -scale and direction notations
3 phases of crime scene search
1) Initial 2) Collection 3) Final
Which f-stop on the camera lens allows for the best depth of field below?
22
what is a wide angle lens used for?
<35 mm, used for interior overalls if distance is UNDER 30 FEET
Which technique does Gardner endorse associated with retrieving latents from human skin?
Adding Machine Paper Technique
Class vs. Individual Characteristics
Class characteristics are not unique to a particular object but place the particular bit of evidence into a group of objects. Individual characteristics narrow down the evidence to a single, individual source.
Who is considered to be the father of the modern crime laboratory?
Locard
Standard evidence plan
Logical progression. This consists of clearing one item of evidence at a time
what are the 3 types of sketches and describe what they are, where they're done/on what?
1) rough sketch: not drawn to scale but must be proportional, may require multiple to depict scene accurately, focus on specific high interest/activity areas, may include observational notes 2) intermediate sketch: post-scene scaled drawing of the crime scene, drafted from the field notes and rough sketch, on 9x11 paper, can be completed on computer 3) final sketch: high quality sketch, usually enlarged, prepared for presentation purposes, may contain only limited depictions of the scene or evidence after consultation with prosecutor or presenter
what is an exploded sketch/cross-projection?
This sketch combines the standard bird's eye view along with the vertical surfaces such as the walls laying flat.
Basic goal of crime scene processing
To collect as much information and evidence as possible, in as pristine condition as possible
What does Gardner say are the two team compositions before performing a systematic search?
area and function
who was edmund locard?
came up with the principle of exchange, stating that every contact leaves its trace
Who does the initial officer release responsibility of the scene once they arrive?
crime scene technician or detective
What does Gardner call a mid-range photo?
evidence establishing shot
What are the 3 types of fingerprint evidence?
latent, patent, plastic
where do we document our evidence notes?
measurement grid sheets
What are the types of evidence pictures and describe them.
-Evidence identification (as it sits) -Evidence documentation (getting more detail) -Examination quality (maximize depth of field, 100 iso)
Steps of road mapping
1) recognition of discrete patterns or defects 2) placement of appropriate labels and scales 3) creation of overall photographs of an area with labels in place 4) creation of overall photographs with labels in space 5) creation of additional evidence - establishing photographs of individual stains or details when needed 6) creation of close-up photographs of individual stains, defects, or details with labels in place
when fingerprint lifting and placing fingerprints on a card, you must document the orientation on the lift card (T/F)
TRUE
The main difference between the strip and line search method is:
number of searchers
who was paul kirk?
one of the first to refer to his work at "scene reconstruction"
The purpose of these photographs is to depict the general conditions and layout of the scene.
overall
Three camera control issues that Gardner describes in this chapter and create poor photographs these are:
physical control, light, focus and depth of field
The most intrusive action of the "basic actions of scene processing is which of the six?
processing/analyzing
The purpose of the criminal investigation still remains first and foremost a _____
search for truth
In Gardner's way of documenting overall observations he talks about an eight-step descriptive set. Which of the following is not in his list of eight? And what are the others? -quantity -condition -color -smell
smell 1)Quantity 2)Item 3)Color 4)Type of Construction 5)Approximate Size 6)Identifying features 7)Condition 8)Location
The initial officer interview by the crime scene investigator is very important. In this interview several things must be covered. Which below best describes "Scope and Nature"?
specific boundaries and reasons why areas were included and impressions of the nature of the crime
rectangular coordinates
technician fixes the evidence by measuring at right angles from the evidence to the surrounding walls and surfaces, not usually very accurate due to odd shapes of objects and you can't fix an orientation of an object
What are the 3 questions that an investigator asks about evidence when they encounter it?
1) what is this item and how was it used? 2) in what way will this item define the crime or sequence the actions associated with the crime? 3) what relational links will this item establish between the scene, the subject, and the victim?
How many photos to fully capture a footwear impression with a photo?
14 - mid range, close up without scale, 12 close up examination quality
Who found the mechanism of mapping variable regions of the DNA molecule?
Jefferys
Gardner recommends this process when the surface you are trying to fingerprint is porous and wet.
Seize, dry, physical developer
The standard broadband filter that is a standard blue light associated with ALS has a 390-520nm range.
TRUE
What is a fracture match?
a mechanical fit; where an item is damaged and pieces are deposited into the scene
what are the 3 things to get photography into court?
accurate, authentic, relevant
what wavelength is the visible spectrum?
between 400 and 700 nm
What subsection of crime scene reports is intended to identify who worked the scene examination, where the scene was, and what time/date of the examination was?
introduction
How do you document blood spatter?
road mapping photograph technique
superglue technique
Cyanoacrylate: this is a fingerprinting technique invented by the Japanese in the 1970s. It is a fuming technique that stabilizes the print and then it can be dyed using rhodamine 6G, Androx, or basic yellow dyes.
Which of the following is not one of the five basic elements of a sketch? -heading -scale and direction notations -notes -title block -legend And what is the missing element?
Notes are not included. Diagram area is missing.
Which filter keeps original wavelength from passing but allows fluorescence energy to pass and be seen?
barrier
how is UV sometimes dangerous to health?
can cause UV burns which are similar to sunburns, and can also damage DNA at the scene
Which problem is not listed by Gardner in crime scene photography?
duplication problems
The footwear impression collection technique that charges a mylar type film to produce a static charge....
electrostatic dust lift
This type of photograph includes landmarks and a recognizable view of the scene and it orients the evidence to the scene.
evidence establishing
What are the 3 elements of crime scene documentation?
photography, notes, sketching
Cyanoacrylate fuming can expose the technician to irritants when used in unventilated areas.
TRUE
It is often for the crime scene team after assessment of the initial scene boundary assessment to change the boundaries.
TRUE
The ability of an initial responding officer to delineate who said what and at what point they said it can be critical when investigators are evaluating who actually know what and when.
TRUE
The technician should create close ups both with and without a scale for reference. Lawyers have argued that placing a scale in the scene somehow materially altered the essence of the photograph hiding critical evidence.
TRUE
There are several methods for crime scene mapping. This coordinate technique requires a placement of a measuring tape in a straight line from some reference point, the 0.0 would be identified as a datum.
baseline
The vast majority of crime scene sketches are produced:
birds eye view
What are the three components of a firearm discharge that is present in what Gardner calls GSR, which our lab refers to as just PR?
lead, barium, antimony
What are the systems that combine transits, lasers, and computer technology to create accurate scaled drawings?
total station
The Forensic Science Academy and Gardner have differences associated with how we describe environmental conditions when noting surroundings. Which one below is how he describes this section of his report?
weather conditions
In glass fracture evaluations, what is concentric vs. radial fractures (be specific about direction of force, what are scientists looking for?)
-4R rule is the method to establish in which direction force was applied to glass, and it is to locate radial fractures that are within the first concentric fracture -4R rule says that ridge lines on radial fractures are at right angles to the rear -radial: radiate out from a central point in the fracture -concentric: encircle the central area of the fracture at various distances -together, they create a spider web effect -for direction evaluation, you must locate primary radial fractures which are made up by the first concentric fracture and the radial fracture extending out from it
ninhydrin
-The preferred method for locating fingerprints from paper products/porous products -Purple reaction -can be sprayed, dipped, painted
what is depth of field? how do you accomplish it? what's the tool to accomplish the widest depth of field?
-depth of field relates to the focus of the objects in front of and beyond the subject of the photo -the f-stop determines how wide the aperture opens and thus controls the amount of light the film is exposed to -the higher the f-stop, the smaller the aperture, resulting in the introduction of less light, and the more we can limit light, the greater the depth of field in the resulting photograph
systematic approach
-methodical: marked by ordered and systematic habits or behavior systematic: purposefully regular -this approach is an organized method of solving a problem, what is necessary to carry out an all-encompassing and detailed search in which little will be overlooked
There are different ways to alter a scene after the incident took place, Gardner calls this scene integrity issues. What are these integrity issues?
-movement of materials -destruction of materials -addition of materials
what are Gardner's essentials for headings in a sketch?
-notation indicates why sketch was created -location -case # -date/time -person conducting sketch
what are the measuring/mapping techniques and describe them?
-rectangular coordinates -triangulation -baseline coordinates -polar coordinates -triangulation or rectangular coordinates on a grid -triangulation on a baseline -total station systems
The technician's narrative scene descriptions should be all of the following:
1) accurate with few inferences or subjective evaluations included 2) detailed with pertinent facts and conditions documented 3) understandable: logical and organized
The Virginia model has three phases as you have seen during lecture. The collection of evidence occurs mostly in the collection phase but what step in Gardner's model does the collection of evidence occur?
10
Ross Gardner used the USACIDC processing model when he was an Army Investigator. How many steps does this model have?
17
How many "recheck" steps in the Gardner model are there?
3
If the patrol officer is the first responder he/she should never take any photographs of the scene because that is not his/her job.
FALSE
Elevation sketch is a sketch done where the elevation is above 1000 feet above sea level
FALSE, it is a drawing depicting a side view of some portion of the scene, typically a vertical cabinet or a wall.
At any crime scene, the technician will apply the following actions to any evidence found there: Assessing Observing Documenting Collecting Processing Which action is missing?
Searching
Forensic Linkage Triangle
The forensic linkage triangle reminds the investigator that items of evidence are used to establish specific links or relationships between the suspect, victim, and scene. Every piece of evidence is considered against this concept to determine whether any links exist and if they are of evidentiary value. The nature of these links may or may not serve to illuminate investigative issues. This is particularly true in our consideration of trace evidence.
What is road mapping and who is credited with that technique?
Toby Wolson - documentation procedure for bloodstained scenes - default procedure for bloodstain documentation - also effective in documenting bullet defects and trajectory analysis - introduces a variety of scales and labels that become the landmarks in the overall photographs to eliminate confusion for the viewer - never a part of initial crime scene documentation because it is intrusive and requires movement of objects
How complex is the scene? How can risks be mitigated if present? These are questions one must ask one's self in the _________ part of the basic activities of scene processing.
assessing
baseline coordinates
best suited for exterior scenes without evident landmarks but can also be used inside, begins with a datum point which is a location from which a baseline will extend, it is set by triangulating with a set of nearby landmarks. once set, baseline can be extended along a cardinal direction and it must be straight, then all objects are measured with a right angle from the baseline (+Y and either -X or +X direction)
The best way to create a crime scene report for any complex scene is to organized the report into sections that deal with specific issues. Which section below deals with cleanliness, level of disarray, and descriptions of the evidence?
condition of the scene
An investigator must understand the evidence's ______________ value to understand how the incident took place. Merely owning the pieces of the puzzle is not enough. Individual facts do not solve a case.
contextual
Nature of the ground being searched, lighting conditions, on scene environmental conditions, size of the items searched for are all examples of:
crime scene search considerations
Every time you go up one f-stop, what happens to the light? f/5.6 -> f/4.0
doubles the amount of light that gets through the lens?
triangulation
effective for fixing evidence, typical landmarks are base corners of walls and doors, in crowded spaces you may have to use a reference point (RP) along the wall and identify it with something like a post it and then measure the distance of the RP to a nearby base corner, there will be 4 measurements for regular shaped items (2 triangles) and 2 for irregular (1 triangle), after triangulating one item of evidence you cannot use that item for to triangulate another item
polar coordinates
effective technique for mapping exterior scenes in which the evidence is scattered over a relatively open area, utilizes a sighting device
What is often used in lieu of other documents to show where all items of evidence were located in the scene and by whom?
evidence log
When considering the context of evidence, Rynearson and Chisum classified contextual value into "types of effects". When you at the crime scene are trying to determine if a lock of a window actually works it falls into this effect catagory.
functional
Gardner states that ballistic evidence should be packaged ________________ to prevent confusion of where it was collected and to prevent the damage of microscopic markings.
individually
What is Gardner's term to describe artifacts/movement of materials in a scene?
integrity issues
Why is the order or sequence of the scene process so important?
it is a one-shot operation
Which element area is where you will find the labels used in the diagram that reduce clutter in the diagram itself?
legend
what are the 3 headings in an intermediate sketch?
legend, key (evidence), symbols
what are the 3 different types of fingerprints?
loops, whorls, arches
black fingerprint powder
mainstay method for nonporous surfaces (as well as magnetic powder)
What is the type of DNA that can be found in bone and hair of a body exposed to the elements with no soft tissue left that can be compared to the DNA of the maternal line of related individuals?
mitochondrial
triangulation on a baseline
not too widely scattered scene and no adequate landmarks, mark RPs at recurring points along the baseline then use standard triangulation
What are the four key elements of crime scene documentation?
notes, photography, sketches, reports
Good quality photographs at a crime scene require:
physical control of camera, proper use of camera controls, proper composition
Procedure for documenting bloodstain scenes through a systematic process created by Toby Wolson.
road mapping
Which one of the following areas should not be brought under control when establishing the initial perimeter of the crime scene?
secondary focal points
As a crime scene investigator in order to function alongside others in the investigation there are a set of "rules" and "customs" that are followed. Responsibilities are outlined for each person in the investigation.
standard operating procedures
What is the purpose of processing the crime scene?
to collect as much information and evidence as possible in as pristine a condition as possible
Gardner's definition of this technique requires a total of four straight line measurements from two distinct landmarks in the room to two distinct points on the article.
triangulation
Sometimes you have to do a combination of two techniques for mapping a crime scene. In situations involving exterior crime scenes where the field of evidence is not too widely scattered but where there are no adequate landmarks.
triangulation on a baseline