Searching For/Collecting Evidence(2)

Searching For/Collecting Evidence(2)

SFS1- Recognize and classify various types of evidence in relation to the definition and scope of Forensic Science: c. Determine the proper techniques to search, isolate, collect and record physical and trace evidence, d. Evaluate the relevance of possible evidence at the site of an investigation, e. Organize relevant information to accurately develop and submit both scene and analysis reports

Directions: Take out one piece of paper and watch the video carefully.

Follow the instructions shown in the video to make a druggist fold with your piece of paper.
Then answer the questions below:

How many “squares” should your paper have after folding it? 6 9 12 16
Why do we use this paper-folding technique for small pieces of evidence? Give two reasons:
______
______

Part IV: Tools for Evidence Collection

the well-prepared ______arrives at a crime scene with a large assortment of ______materials and _____, ready to encounter any type of situation:
forceps (______) and similar tools may have to be used to pick up _____ items
unbreakable ______pill bottles with ______lids are excellent containers for hairs, _____, fibers, and various other kinds of small or _____ evidence
______envelopes, _____-___ glass vials, or ______pillboxes are also adequate ______for most trace evidence encountered at crime sites
ordinary ______envelopes should not be used as evidence containers because ______and fine ______willleak out of their unsealed______
small amounts of trace evidence can also be conveniently packaged in a carefully ______paper, using what is known as a “______fold.”
fold one end of the paper over one-_____, then fold the other end (one-third) over that
______the process from the other two sides
after the paper is folded in this manner, ____ the outside two ______into each other
this produces a ______container that keeps the ______from falling out
guidelines for packaging of evidence:
for ______materials, wrapping paper, manila envelopes, or ______are used
in airtight containers, the accumulation of ______may encourage the growth of _____, which can destroy the ______value of ______
all items of clothing are ___-_____ and placed ______in separate paper bags to ensure constant ______of air through them
______debris recovered from the scene of a ____is sealed in an airtight container to prevent the ______of volatile______residues
____ paint cans or tightly sealed _____ are recommended
a ______description of the proper collection and packaging of various types of physical evidence is ______in the evidence guide found in Appendix I (pages _____ - _____)

Why should ordinary mailing envelopes not be used for evidence? ______

A new paint can would be a good container what sort of evidence? ______

Part V: Maintaining the Chain of Custody

continuity of ______, or the _____ of custody, must be established whenever evidence is presented in _____ as an ______
chain of custody= a ____ of all the ______who came into possession of an item of ______
to ensure evidence will withstand inquiries how it was handled, adherence to ______procedures is required when:
recording the ______ of evidence,
marking it for ______, and
properly completing evidence submission_____
this means that ______person who handled/examined the evidence must be ______for
failure to ______the evidence’s chain of custody may lead to serious questions regarding the ______and ______ of the evidence and ______of it
all items of physical evidence should be carefully packaged and ______upon their retrieval at crime sites to avoid ______their evidential value or ______the number and kind of examinations to which they may be ______by the criminalist
if at all possible, the evidence ______ should be marked for identification (the collector’s ______and the _____ of collection are inscribed ______on the article)
when appropriate, the evidence is ______ for identification
evidence in ______containers (in a ____, bag, ____, or can) is marked on the ______
records should show the ______’s initials, location of the evidence, and collection date
if the evidence is turned over to another ______ for care or ______to the lab, this transfer must be ______in notes and other appropriate _____
in fact, every individual who ______the evidence must maintain a ______of its acquisition and disposition
frequently, all of the individuals involved in the collection and ______of evidence may be requested to ______ in court
to avoid confusion and to retain ______of the evidence at all times, the chain of custody should be kept to a ______

True or False: Labels can be placed directly on evidence. ______

Part VI: Obtain Standard/Reference Samples

the examination of evidence, whether _____, blood, glass, hair, ______, and so on, often requires ______with a known ______/______sample
standard/reference sample = physical evidence who origin is ______, such as blood or hair from a ______, that can be ______to crime scene evidence
an investigation of a hit-and-run incident might require the removal of reference ______ from a suspect ______(to compare to paint recovered at the _____)
hair found at the crime scene will be of ______value only when compared to reference hairs removed from the ______and ______
bloodstained evidence must be accompanied by a _____-_____ or buccal swabreference ______obtained from all victims and suspects
buccal swab = a swab of the ______, performed to collect ______for use in determining the ______of an individual
the quality and ______ of standard/reference specimens often determine the ______of crime-scene evidence
some types of evidence must also be accompanied by the collection of ______controls
substrate controls = ______surface material _____ to an area where physical evidence has been ______
used to ensure the ______on which a sample has been deposited does not ______with lab ______—for example:
at arson scenes, if an investigator suspects that a particular surface has been exposed to ______or some other ______, the investigator should also collect a piece of the same ______that is believed notto have been ______to the accelerant
for bloodstained evidence, unstained areas _____ to the stain may be sampled for the purpose of determining whether the material will have an ______on lab results
thorough ______and proper ______of standard/reference specimens and substrate controls are the mark of a ______forensic technician

A buccal swab is taken from the ______of the victim/suspect.

True or False: Substrate controls contain evidence. ______

Part VII: Submitting Evidence to the Laboratory

evidence is usually ______to the laboratory either by ______delivery or by _____
the ______of transmittal is determined by the ______ the submitting agency must travel to the laboratory and the ______ of the case
if the evidence is delivered personally, the deliverer should be ______with the case, to facilitate any ______between lab personnel and the deliverer concerning specific ______of the case
if desired, most evidence can be ______by mail
postal ______ restrict the shipment of certain

chemicals and ____ ammunition and ______the mailing of explosives

evidence must be carefully packaged in order to prevent ______or other accidental ______while is ______to the lab

most labs require an ______on all evidence submitted:
when ______completed, its information will enable the lab______to make an intelligent and ______examination of the evidence
particular attention should be paid to providing the lab with a brief ______of the case history—this information will allow the examiner to analyze the ______in a ______sequence and make the proper ______, and it will also facilitate the search for trace ______of evidence
the particular ____ of examination requested for each type of evidence is to be requested on the form, but the analyst is not be bound to ______to the specific tests requested by the investigator
finally, a ____ of items submitted for examination must be included on the evidence submission form—each item is to be packaged ______and assigned a ______or letter, which should be listed in an ______and ______sequence on the form

True or False: Explosive material evidence can be sent through the mail. ______

Searching For/Collecting Evidence (2)

Directions: Take out one piece of paper and watch the video carefully.

Follow the instructions shown in the video to make a druggist fold with your piece of paper.
Then answer the questions below:

How many “squares” should your paper have after folding it? 6 9 12 16
Why do we use this paper-folding technique for small pieces of evidence? Give two reasons:
______
______

Part IV: Tools for Evidence Collection

the well-prepared evidence collector arrives at a crime scene with a large assortment of packaging materials and tools, ready to encounter any type of situation:
forceps (tweezers) and similar tools may have to be used to pick up small items
unbreakable plastic pill bottles with pressure lids are excellent containers for hairs, glass, fibers, and various other kinds of small or trace evidence
manila envelopes, screw-cap glass vials, or cardboard pillboxes are also adequate containers for most trace evidence encountered at crime sites
ordinary mailing envelopes should not be used as evidence containers because powders and fine particles will leak out of their unsealed corners
small amounts of trace evidence can also be conveniently packaged in a carefully folded paper, using what is known as a “druggist fold.”
fold one end of the paper over one-third, then fold the other end (one-third) over that
repeat the process from the other two sides
after the paper is folded in this manner, tuck the outside two edges into each other
this produces a closed container that keeps the specimen from falling out
guidelines for packaging of evidence:
for bloodstained materials, wrapping paper, manila envelopes, or paper bags are used
in airtight containers, the accumulation of moisture may encourage the growth of mold, which can destroy the evidential value of blood
all items of clothing are air-dried and placed individually in separate paper bags to ensure constant circulation of air through them
charred debris recovered from the scene of a fire is sealed in an airtight container to prevent the evaporation of volatile petroleum residues
new paint cans or tightly sealed jars are recommended
a detailed description of the proper collection and packaging of various types of physical evidence is summarized in the evidence guide found in Appendix I (pages 700 – 711)

Why should ordinary mailing envelopes not be used for evidence? ______

A new paint can would be a good container what sort of evidence? ______

Part V: Maintaining the Chain of Custody

continuity of possession, or the chain of custody, must be established whenever evidence is presented in court as an exhibit
chain of custody= a list of all the people who came into possession of an item of evidence
to ensure evidence will withstand inquiries how it was handled, adherence to standard procedures is required when:
recording the location of evidence,
marking it for identification, and
properly completing evidence submission forms
this means that every person who handled/examined the evidence must be accounted for
failure to substantiate the evidence’s chain of custody may lead to serious questions regarding the authenticity and integrity of the evidence and examinations of it
all items of physical evidence should be carefully packaged and marked upon their retrieval at crime sites to avoid destroying their evidential value or restricting the number and kind of examinations to which they may be subjected by the criminalist
if at all possible, the evidence itself should be marked for identification (the collector’s initials and the date of collection are inscribed directly on the article)
when appropriate, the evidence is tagged for identification
evidence in sealed containers (in a box, bag, vial, or can) is marked on the container
records should show the collector’s initials, location of the evidence, and collection date
if the evidence is turned over to another individual for care or delivery to the lab, this transfer must be recorded in notes and other appropriate forms
in fact, every individual who possesses the evidence must maintain a written record of its acquisition and disposition
frequently, all of the individuals involved in the collection and transportation of evidence may be requested to testify in court
to avoid confusion and to retain complete control of the evidence at all times, the chain of custody should be kept to a minimum

True or False: Labels can be placed directly on evidence. ______

Part VI: Obtain Standard/Reference Samples

the examination of evidence, whether soil, blood, glass, hair, fibers, and so on, often requires comparison with a known standard/reference sample
standard/reference sample = physical evidence who origin is known, such as blood or hair from a suspect, that can be compared to crime scene evidence
an investigation of a hit-and-run incident might require the removal of reference paint from a suspect vehicle (to compare to paint recovered at the scene)
hair found at the crime scene will be of optimum value only when compared to reference hairs removed from the suspect and victim
bloodstained evidence must be accompanied by a whole-blood or buccal swabreference sample obtained from all victims and suspects
buccal swab = a swab of the inner cheek, performed to collect cells for use in determining the DNA profile of an individual
the quality and quantity of standard/reference specimens often determine the evidential value of crime-scene evidence
some types of evidence must also be accompanied by the collection of substrate controls
substrate controls = uncontaminated surface material close to an area where physical evidence has been deposited
used to ensure the surface on which a sample has been deposited does not interfere with lab tests—for example:
at arson scenes, if an investigator suspects that a particular surface has been exposed to gasoline or some other accelerant, the investigator should also collect a piece of the same surface material that is believed not to have been exposed to the accelerant
for bloodstained evidence, unstained areas close to the stain may be sampled for the purpose of determining whether the material will have an impact on lab results
thorough collection and proper packaging of standard/reference specimens and substrate controls are the mark of a skilled forensic technician

A buccal swab is taken from the ______of the victim/suspect.

True or False: Substrate controls contain evidence. ______

Part VII: Submitting Evidence to the Laboratory

evidence is usually submitted to the laboratory either by personal delivery or by mail
the method of transmittal is determined by the distance the submitting agency must travel to the laboratory and the urgency of the case
if the evidence is delivered personally, the deliverer should be familiar with the case, to facilitate any discussions between lab personnel and the deliverer concerning specific aspects of the case
if desired, most evidence can be shipped by mail
postal regulations restrict the shipment of certain

chemicals and live ammunition and prohibit the mailing of explosives

evidence must be carefully packaged in order to prevent breakage or other accidental destruction while is in transit to the lab

most labs require an evidence submission form on all evidence submitted:
when properly completed, its information will enable the lab analyst to make an intelligent and complete examination of the evidence
particular attention should be paid to providing the lab with a brief description of the case history—this information will allow the examiner to analyze the specimens in a logical sequence and make the proper comparisons, and it will also facilitate the search for trace quantities of evidence
the particular kind of examination requested for each type of evidence is to be requested on the form, but the analyst is not be bound to adhere strictly to the specific tests requested by the investigator
finally, a list of items submitted for examination must be included on the evidence submission form—each item is to be packaged separately and assigned a number or letter, which should be listed in an orderly and logical sequence on the form

True or False: Explosive material evidence can be sent through the mail. ______

Forensic Pathology. This field involves the investigation of sudden, unnatural, unexplained, or violent deaths. Typically, forensic pathologists, in their role as medical examiners or coroners, must answer several basic questions: Who is the victim? What injuries are present? When did the injuries occur? Why and how were the injuries produced? The primary role of the medical exam-iner is to determine the cause of death. If a cause cannot be found through observation, an au-topsy is normally performed to establish the cause of death. The manner in which death occurred is classified into five categories: natural, homicide, suicide, accident, or undetermined, based on the circumstances surrounding the incident.

After a human body expires, it goes through several stages of decomposition. A medical ex-aminer participating in a criminal investigation can often estimate the time of death by evaluat-ing the stage of decomposition in which the victim was found. Immediately following death, the muscles relax and then become rigid. This condition, rigor mortis, manifests itself within the first twenty-four hours and disappears within thirty-six hours. Another condition occurring in the early stages of decomposition is livor mortis. When the human heart stops pumping, the blood begins to settle in the parts of the body closest to the ground. The skin will appear dark blue or purple in these areas. The onset of this condition begins immediately and continues for up to twelve hours after death. The skin will not appear discolored in areas where the body is restricted by either clothing or an object pressing against the body. This information can be useful in de-termining if the victim’s position was changed after death occurred.

Other physical and chemical changes within the body are also helpful in approximating the time of death. Algor mortis is the process by which the body temperature continually cools after death until it reaches the ambient or room temperature. The rate of heat loss is influenced by fac-tors such as the location and size of the body, the victim’s clothing, and weather conditions. Be-

cause of such factors, this method can only estimate the approximate time period since death. As a general rule, beginning about an hour after death, the body will lose heat at a rate of approxi-mately 1–1.5°F per hour until the body reaches the environmental temperature.

Another approach helpful for estimating the time of death is determining potassium levels in the ocular fluid (vitreous humor). After death, cells within the inner surface of the eyeball release potassium into the ocular fluid. By analyzing the amount of potassium present at various inter-vals after death, the forensic pathologist can determine the rate at which potassium is released into the vitreous humor and use it to approximate the time of death. During the autopsy, other factors may indicate the time period in which death occurred. For example, the amount of food in the stomach can help estimate when a person’s last meal was eaten. This information can be valuable when investigating a death.