Flashcards in Physical Evidence Deck (54):
What are the three types of evidence?
Statements made by witnesses, victims, or suspects is what type of evidence?
Any type of written evidence is what type of evidence?
What type of evidence is also known as real evidence?
True of False: Physical evidence may be visible or invisible?
What type of evidence helps establish the elements of the crime, links scene, suspect and victim, and identify persons involved?
What is the Theory of Interchange?
Every contact leaves a trace
Who developed the Theory of Interchange?
Doctor Edmond Locard
What are the two characteristics of evidence?
What are class characteristics?
Those characteristics which can be associated with a family of objects
What are individual characteristics?
Characteristics of items which are caused by natural or chance occurrences, use and abuse, or wear and tear which will allow the impressions made by an item to be matched back to the item through forensic examination or mechanical matching
What are the three photographic views of scene/evidence necessary?
How do sketches aid in evidence documentation?
Sketches are used to show location and distance relationships between relevant items within the scene
What information is always included on sketches?
* Title block (case number, date, type of case, sketcher, location, and other information as required by agency)
* "Not to scale" notation, and
* North arrow (compass direction)
* Evidence indicated by numbers
* Fixed points/large objects indicated by letters
A sketch legend includes what four items?
* explanation of symbols used on sketch(es)
* Items of evidence
* Photo points
What type of measurement is generally considered the most accurate method of plotting the position of items on a sketch?
How are triangulation measurements performed?
Triangulation is used to plot the position of an item by measuring from two or more fixed points to two or more points on the item to be located.
What are straight line measurements used for?
Used to measure room dimensions or to locate items along a wall
When are rectangular measurements used?
Used to locate items 90 degrees off of a wall
What are the six types of search methods?
1. Zone or sector
6. Point to point
When is the zone search method used?
* Used inside or outside
* Breaks large areas into smaller, more manageable sections
When is the Clockwise/counterclockwise search method used?
* Useful indoors
* Search is conducted from eye level up, and eye level down, in clockwise and counterclockwise directions, the repeated
What type of search method is often used underwater when visibility is limited?
When is the strip search method used?
* Used outdoors
* A number of searchers line up side by side and search in lines until the complete area has been searched
What is the grid search method?
* Basically two strip searches superimposed at 90 degree angles to one another
* Goes over the same area twice
When is the point to point search method used?
* Used in small confined spaces
* Unsystematic and may lead to the inadvertent destruction of evidence
What are some types of fragile evidence?
What type of container is clothing packaged in?
A porous container
What do you do if clothing evidence is wet?
Air dry naturally on a plastic hanger with clean paper beneath it
What are comparison standards?
Known samples to be compared to unknown samples of like substances
Fingerprints on porous surfaces, that are not visible, are developed with what?
If not visible, fingerprints on non-porous surfaces are developed with what?
How should firearms at a crime scene be packaged?
In a sturdy container and in a manner that will prevent movement of the gun
To prevent damage to hairs or fiber evidence, how should it be collected?
Collect with soft forceps, gloved hands, or other method to prevent damage to item
How should hair or fiber evidence be packaged?
In either a pharmacists fold (folded paper), or a pillbox
Narcotics and other drugs should be packaged in what type of container?
In a non-porous container, except moist, leafy materials
Moist, leafy drugs should be packaged in what type of container?
A porous container until it dries out
A chain of custody does what?
Documents evidence from the time it is discovered until no longer needed by the court
What information should be included on the chain of custody document?
* Agency case number, item number
* Who found and who collected the evidence with the date and time if different people handled it
* Location and/or person from whom recovered
* Tag large items, package and label smaller items
How many copies of a letter of transmittal should be included with the evidence sent to the lab?
Two, one inside the package and one outside the package
Live ammunition, being shipped to the lab, should be sent via what carrier?
All evidence, except live ammunition and firearms, sent to the lab, should be sent via what carrier?
Firearms sent to the lab should be sent via what carrier?
What are the four components of documents?
What are the two identifiers of Paper?
Who keeps the ink library?
True or false: the year ink was manufactured can be determined?
What are five types of writing instruments?
* Ball point pen
* Roller ball
* Fountain pen
* Porous tip pen
* Pencil, etc.
What type of machine is the easiest to identify?
How are color copiers identified?
Color copiers use a pattern of yellow dots, left on the paper, to ID different machines
What are "trash marks"?
Machines can be traced to a document through "trash marks" caused through normal wear and tear through use.
What are three key points about handwriting?
* Unique to an individual
* Can be affected by age, drugs or alcohol, health, conscious attempt to disguise, etc.
* No 5th or 6th amendment violations
What are pros and cons of Request exemplars?
* Can be dictated
* Are known samples
* Can be taken to the satisfaction of the investigator
* Usually no admissibility problems
* Attempt to disguise must be factored into the writing
* May be a significant lapse of time since the original was written
* Obtain samples early in the interview
* Do not let the suspect see or handle the original document
* Make a note of any special instructions or circumstances surrounding the exemplar