Copyright and Terms of Service

Size: px

Start display at page:

Download "Copyright and Terms of Service"

Alison Hill
8 years ago
Views:

1 Forensic Science

2 Copyright and Terms of Service Copyright Texas Education Agency, These materials are copyrighted and trademarked as the property of the Texas Education Agency (TEA) and may not be reproduced without the express written permission of TEA, except under the following conditions: 1) Texas public school districts, charter schools, and Education Service Centers may reproduce and use copies of the Materials and Related Materials for the districts and schools educational use without obtaining permission from TEA. 2) Residents of the state of Texas may reproduce and use copies of the Materials and Related Materials for individual personal use only, without obtaining written permission of TEA. 3) Any portion reproduced must be reproduced in its entirety and remain unedited, unaltered and unchanged in any way. 4) No monetary charge can be made for the reproduced materials or any document containing them; however, a reasonable charge to cover only the cost of reproduction and distribution may be charged. Private entities or persons located in Texas that are not Texas public school districts, Texas Education Service Centers, or Texas charter schools or any entity, whether public or private, educational or noneducational, located outside the state of Texas MUST obtain written approval from TEA and will be required to enter into a license agreement that may involve the payment of a licensing fee or a royalty. Contact TEA Copyrights with any questions you may have. 2

3 Isolate and secure the scene Document the scene Search for evidence Collect and package the evidence while maintaining the chain of custody Submit the evidence for analysis 3

4 A Assess the crime scene and assist the injured D Detain the witness(es) A Arrest the perpetrator P Protect the crime scene T Take notes 4

5 1) Look for signs of life 2) Cordon off the scene (only allow authorized personnel in) 3) Bodies should be certified as dead by a medical examiner (ME) before being moved 5

6 A walkthrough is performed by the crime scene investigator, the first officer, and sometimes the lead detective Record initial observations of who, what, where, when, and how Make a plan of action 6

7 Record the crime scene and potential evidence with Notes Photography Sketches Videography 7

8 Record the following while at the crime scene (details are the key): Date Time Description of the location, weather, and environmental conditions Description of the crime Location of the evidence relative to other key points Names of all people involved Any other relevant information 8

9 Nothing should be moved until photographed Take photos of the scene and the surroundings Photograph entrances and exits Take wide and close-up photos Use various angles for each piece of evidence Use a ruler to show size 9

Draw a rough sketch at the scene (reconstruct it better later) Include Date, time, and location Scale Recovered items Important features Accurate distance

10 Draw a rough sketch at the scene (reconstruct it better later) Include Date, time, and location Scale Recovered items Important features Accurate distance measurements of objects (from two fixed points) A legend for description of items A compass designating north Names of investigators, victims, and suspects 10

11 11

12 Narrate the video Be objective Record from different perspectives 12

13 Triangulation For each piece of evidence being recorded, use two permanent objects as reference points that are not likely to be moved The two reference points and the piece of evidence form a triangle, hence the term triangulation Whatever object you are measuring to or from, use the same spot on the object every time 13

Rectangular Coordinates Baseline The simplest form of the rectangular coordinate system Using a straight line between two known points, items are measured along the line and then

14 Rectangular Coordinates Baseline The simplest form of the rectangular coordinate system Using a straight line between two known points, items are measured along the line and then measured perpendicular to the line Inside or outside of a house, this line can be a straight wall Outdoor scenes can use a string or long measuring tape as the reference or baseline 14

15 Rectangular Coordinates Grid Measure the distance of items from two perpendicular baselines This technique is particularly appropriate in a room with perpendicular walls or outdoors with perpendicular streets 15

16 Polar Coordinates Measure both the distance and the direction (angle) an object is from a known reference point For example, 40 feet from the edge of the house and 15 degrees east of north 16

17 When searching a crime scene, wear the following, if available, to minimize contamination Disposable gloves Masks Coveralls with a hood Slippers 17

18 Depend on the size and the location of the crime scene and the number of investigators available Stick to one pattern and one supervisor Better to collect everything and not need it than fail to collect something and need it later 18

19 Spiral may move inward or outward; best used where there are no physical barriers Grid basically a double-line search; effective, but time-consuming Line (Strip) best in large, outdoor scenes Zone (Quadrant) most effective in houses or buildings; teams are assigned small zones for searching 19

20 Spiral Grid Strip or Line Quadrant or Zone 20

21 Physical evidence must be packaged and collected before time and weather can alter it Physical evidence any object that can establish that a crime has been committed or links a crime and the victim or suspect The Golden Hour the window of opportunity to collect time-sensitive information or evidence 21

22 Each item must be placed in a separate container, and sealed and labeled The most fragile evidence is collected and packaged first Different types of evidence require specific or special collection and packaging techniques The body is the property of the coroner or medical examiner; collection of evidence on the body is done by that department 22

23 Containers such as vials, envelopes, plastic bags, paper bags, canisters, and cardboard boxes are good packaging devices Most items should be placed in a primary container and then in a secondary container Trace evidence may be placed on a piece of paper which is then folded in a druggist fold and placed in a secondary container 23

24 Containers should be sealed with tamper proof tape, and dated and initialed Each package should contain Date, time, and location Case number Agency and collector s name Victim s name(s) Description of contents Never package two items from two different sources or locations 24

25 There must be a written record of all people who have had possession of an item of evidence, beginning at the time of collection Every person who handled or examined the evidence must be accounted for Chain of Custody should include Date and time of transfer Location of transfer To/From names Purpose of the transfer 25

26 Crime Scene Investigators can submit evidence for analysis to several national databases based on the type of evidence Examples include Automated Fingerprint Identification System (AFIS) Integrated Automated Fingerprint Identification System (IAFIS) Combined DNA Index System (CODIS) Integrated Ballistics Identification System (IBIS) International Forensic Automotive Paint Data Query (PDQ) 26

0135158494, Saferstein, Richard. Forensic Science: An Introduction. New Jersey: Pearson Prentice Hall, 2008.

27 , Saferstein, Richard. Forensic Science: An Introduction. New Jersey: Pearson Prentice Hall, , Ball-Deslich, Barbara and John Funkhouser. Forensic Science for High School. 2 nd Edition. Kenall/Hunt,

Course Forensic Science. Unit IV Crime Scene Investigation

Course Forensic Science. Unit IV Crime Scene Investigation Course Forensic Science Unit IV Crime Scene Investigation Essential Question What procedures are implemented at a crime scene and why are they important? TEKS 130.295(c) (1)(A)(B) (2)(F H) (3)(A F) (5)(A