Name: ________________________ Period: _________

Forensic ScienceCrime Scene Investigation

I. Process a Crime Scene A. Isolate and _______________ the sceneB. Document the sceneC. Search for the _______________D. Collect and package the evidence while maintaining the chain of custodyE.____________ the evidence for analysis

II. First Officer on the Scene A – ______________the crime scene and assist the injuredD – _______________ the witness (es) A – _______________ the perpetratorP – _______________ the crime sceneT – _______________ notes

III. Secure the Crime Scene 1. Look for signs of ____________2. Cordon ______________the scene (only allow authorized personnel in)3. Bodies should be certified as “dead” by a medical examiner (ME)before being _______________

IV. Survey the Crime Scene

A. A walkthrough is performed by the _____________ scene investigator, the first officer, and sometimes the lead detectiveB. Record initial observations of who, what, where, when, and _________________C. Make a plan of _________________

V. Document the Crime Scene A. Record the crime scene and potential evidence with

Notes _______________________ Sketches Videography

1

1. Notes: Record the following while at the crime scene (details are the key)

Date Time Description of the location, weather, and environmental

__________________ Description of the crime Location of the evidence relative to other key points Names of ____________people involved Any other relevant information

2. Photography

________________________ should be moved until photographed Take photos of the _________________ and the surroundings Photograph entrances and exits Take _______________ and close-up photos Use various angles of each piece of evidence Use a ______________ to show size

3. Sketches –

Draw a rough sketch at the scene (reconstruct a better one later) Include

Date, time, and location Scale Recovered _____________________ Important features Accurate distance measurements of objects (from two fixed points) A legend for the description of items A compass designating north _________________ of the investigators, victims, and suspects

2

4. Videography

Narrate the _________________ Be objective Record _______________________ different perspectives

VI. Measuring Techniques

1. Triangulation a. For each piece of evidence being recorded, use ______________ permanent

objects as reference points that are not likely to be movedb. The two reference points and the piece of evidence form a _______________,

hence the term triangulationc. Whatever object you are measuring to or from, use the ______________spot on

the object every time2. Rectangular Coordinates – Baseline

a. The simplest form of the rectangular coordinate systemb. Using a _______________ ______________ between two known points, items

are measured along the line and then measured perpendicular to the linec. Inside or outside of a house, this _________________ can be a straight walld. Outdoor scenes, use a __________________ or a long measuring tape as the

reference or baseline3. Rectangular Coordinates – Grid

a. Measure the distance of the items from _______________ perpendicular base lines

b. This technique is particularly appropriate in a room with perpendicular _____________ or in the outdoors with perpendicular streets

4. Polar Coordinates a. Measure both the distance and the direction (angle) an object is from a

known reference pointb. For example, 40 feet from the ___________________ of the house and 15

degrees east of north

VII. Search the Crime SceneA. When searching a crime scene wear the following, if available, to minimize contamination

o Disposable gloveso _______________o Coveralls with a hoodo Slippers

3

B. Search Patterns1. Depend on the size and the location of the crime scene and the number of

investigators available2. Stick to ____________ pattern and ______________ supervisor3. It’s better to collect everything and not need it than fail to collect something and

need it later4. ________________– may move inward or outward; best used where there are

no physical barriers5. ________________ – basically a double-line search; effective, but time-

consuming6. ______________ (Strip) – best in large, outdoor scenes7. ________________ (Quadrant) – most effective in houses or buildings; teams

are assigned small zones for searching

VIII. Collect and Package Evidence

1. Physical evidence must be packaged and collected before ___________ and weather can alter it

2. Physical evidence – any object that can establish that a crime has been committed or links a crime and the victim or suspect

3. ______________ _____________ ______________ – the window of opportunity to collect time- sensitive information or evidence

4. Each item must be placed in a __________________ container, and sealed and labeled

4

5. The most fragile evidence is collected and packaged _______________6. Different________________ of evidence require specific or special collection and

packaging techniques7. The body is the __________________ of the coroner or medical examiner;collection of

evidence on the body is done by that department8. ___________________ such as vials, envelopes, plastic bags, paper bags, canisters, and

cardboard boxes are good packaging devices9. Most items should be placed in a primary container and then in a secondary container10. Trace evidence may be placed on a piece of paper which is then11. folded in a “druggist fold” and placed in a secondary container12. Containers should be sealed with tamper proof tape, and dated and initialed

L. Each package should containo Date, time, and locationo Case numbero Agency and collector’s nameo Victim’s name(s)o Description of contentso ____________________ package two items from two different sources or

locations

IX. Chain of Custody

A. There must be a written record of all of the people who have had possession of an item of evidence, beginning at the time of the collection

B. Every person who has handled or examined the evidence must be accounted fora. Chain of Custody should include

1. Date and time of transfer2. Location of transfer3. To/From names4. Purpose of the transfer

X.National Databases

A. Crime scene investigators can submit evidence for analysis to several national databases depending on the type of evidence

B. Examples includeo Automated Fingerprint Identification System (AFIS)o Integrated Automated Fingerprint Identification System (IAFIS)o Combined DNA Index System (CODIS)o Integrated Ballistics Identification System (IBIS)o International Forensic Automotive Paint Data Query (PDQ)

5