1. The Crime Scene
Coach Whitaker

2. Vocabulary
Crime Scene—any place where evidence may be located to help explain events
Modus Operandi—the characteristic method of operation of a criminal
Chain of Custody—a written record of all people who have had possession of an item of evidence
Alibi—statement of where a suspect was at the time of a crime.

3. Vocabulary
Accomplice—person associated with someone suspected of committing a crime
Suspect—person thought to be capable of committing a crime
Secondary Crime Scene—an alternate location where additional evidence may be found
Primary Crime Scene—the original location of a crime or accident

4. Crime Scene
What evidence can be found at a crime scene?
Brainstorm with your group to come up with a list of evidence you might find at a crime scene.
What is the difference in a primary and secondary crime scene?
Name some potential primary and secondary crime scenes in the following scenes bank robbery, burglary, murder, theft, assaults.

5. At the Crime Scene
Forensic Science Begins at the Crime Scene which can provide useful information that must be carefully, systemically, scientifically, and legally collected
The information and evidence at the scene that must be used later to reconstruct the scene and events that led up to the crime
It establishes the MO and the motive for the crime

6. At the Crime Scene
The main reason to carefully analyze the crime scene is to learn what happened and to gather evidence to convict the suspect
The CSI’s experience, knowledge, and capabilities are critical for deciding which items at a scene are actual evidence
If errors at made at the scene in protecting, processing, and analyzing the evidence it can be thrown out in court

7. Steps in Handling the Crime Scene
Preserving and Isolating the Crime Scene
Observing and Documenting the scene
Searching the scene for evidence
Collecting and packaging evidence
Maintaining Chain of Custody

8. Crime Scene Personnel
POLICE OFFICERS are typically the first to arrive at a crime scene. They are responsible for securing the scene so no evidence is destroyed and detaining persons of interest in the crime.
The CSI UNIT documents the crime scene in detail and collects any physical evidence.
The District Attorney is often present to help determine if any search warrants are required to proceed and obtains those warrants from a judge.
The MEDICAL EXAMINER (if a homicide) may or may not be present to determine a preliminary cause of death.
SPECIALISTS (entomologists, forensic scientists, forensic psychologists) may be called in if the evidence requires expert analysis.
DETECTIVES interview witnesses and consult with the CSI unit. They investigate the crime by following leads provided by witnesses and physical evidence.

9. Preserving and Isolating the Crime Scene
The first officer on scene determines the nature of the crime and has the following responsibilities:
Get medical assistance if needed (saving lives is the first priority even if it means disturbing the crime scene)
Make an arrest
The scene must be secured and protected against any unauthorized person from entering it
Suspects and witnesses must be detained
Protect and preserve evidence at the scene

10. Preserving and Isolating the Crime Scene
The investigator interviews the first responder, victim, or witnesses to learn what may have happened
Police officers note and record details such as weather conditions, odors, lights, signs or prior activities at the scene, etc

11. Activity Forensic Science on the Net Name ___________________________
CHIN – Interactive Investigator
PDF Worksheet

12. Observing and Documenting the Scene
The investigator should do the following:
Examine the scene to get an overall view to find pieces of evidence
To ID the points of entry and exit
To consider what may have happened
To mentally outline how the scene should be handled
KEEN OBSERVATION AND
DETAILED NOTES ARE
CRITICAL!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

13. Observing and Documenting the Scene
Notes—the most important parts of processing the scene. Why?
Forces investigators to more observant (makes you focus on details you would miss or overlook)
Notes should be complete and written clearly and legibly
They should detail step by step every action that the investigator takes in the order it happened

14. Observing and Documenting the Scene
Notes should include:
Date and time
Location, environment, weather description
Description of the scene
Written description of physical evidence, location, time of discovery, and packaging
Names of the people involved

15. Observing and Documenting the Scene
Photographs
“A picture is worth a thousand words”
Before making any detailed examination or
touching the scene, an investigator must
photograph the scene
Pictures help CSI remember details, show where evidence was placed in the scene, and help jury and judge visualize the scene

16. Observing and Documenting the Scene
The investigator must include photos that:
Clarify the scene
Close up of evidence
Views of the witness
Location and surroundings of the crime
Objects from different angles
Rule to scale
Are documented for evidence

17. Observing and Documenting the Scene
Videotaping
The investigator can narrate relevant information while moving through the scene

18. Observing and Documenting the Scene
Sketches
Sketches give photographs perspective
Gives a permanent record of the relationships of different points of interest to each other in the scene
Gives a better layout
The sketch must have measurements, scale, and correct placement of details
Combines note with photos

19. Activity Sketches, Photos, and videotaping
Investigation Discovery (PDF) AT  

20. Searching the Scene for Evidence
Without evidence even the most heinous crimes will go unpunished
The care that is taken collected evidence directly impacts the police ability to prosecute crimes
Evidence can be damaged, contaminated, or even lost which makes it useless to the crime lab and inadmissible in court

21. Searching the Scene for Evidence
The first step is finding it by taking an orderly approach to search the scene
Many items will be visible while others are not
The way investigators search the scene depends on the size and physical layout of the area in question

22. Searching the Scene for Evidence
Searchers usually following a geometric pattern, some examples include:
Grid Search

23. Searching the Scene for Evidence
Linear Search

24. Searching the Scene for Evidence
Quadrant or Zone

25. Searching the Scene for Evidence
Spiral Search

26. Search Activity Search Using different stories, crimes, and scenes
(Courtyard)

27. Gathering the Evidence
The next step is collect and package the evidence
The investigator must put each item in a separate container and label it
When collecting evidence, investigators start with evidence that is fragile or that is likely to be lost, damaged, or contaminated, such as blood, fibers, hair, fingerprints, shoeprints, and tire tracks

28. Gathering the Evidence
Generally, pill bottles, vials, manila envelopes, and plastic bags are good container for most evidence
Special considerations include:
Wet items must be dried before packaging
Containers must be sealed to prevent leaks or breakage
Biological items should be dried and kept in a freezer

29. Gathering the Evidence
Clothing with trace evidence should be packaged carefully to avoid disturbance
Firearms should be fixed rigidly inside a wooden container
A collection may be made using adhesive tape

30. Gathering the Evidence
Gathering delicate evidence
Fingerprints are photographed and then lifted or transferred to a material
Tool marks and shoeprints or tire impressions are photographed before being lifted or casted
Fibers and hair are searched for with alternative light sources and picked up with tweezers
Carpets and furniture are vacuumed with a clean bag for each area

31. Control Samples
Control Samples are samples with a know origin. For example, blood from a scene compared to the blood of the victim
These control samples must be collected and compared with samples from the scene
All evidence should be sealed with tamper proof tape and properly labeled

32. Gathering Evidence Activity
Search Using different stories, crimes, and scenes
(Courtyard)
Collect Evidence and Package
List for each crime

33. Chain of Custody
There must be a written record of who has had possession of the evidence at all times
The court needs to know who has been responsible for evidence from the time it was collected to time it appears in court

34. Chain of Custody The record will show: Who collected the evidence
Who had contact with the evidence
At what time
Under what circumstances
And if changes where made to the evidence

35. Chain of Custody The record is usually on the package itself
It is not uncommon for everyone who came into contact with the evidence to testify in court

36. Chain of Custody
After the scene has been processed and investigated, evidence is sent to the forensic lab or stored

37. Unit Project Crime Scene Processing Project Elements
(three scenes) (2 Groups)
Secure scene
Invent own crime
Notes, photographs or videos, sketches, search, evidence gathering and packaging, and Chain of Custody
Photostory or Movie maker about crime

38. Checklist for finding five pieces of evidence, chain of custody, Crime scene log,
Draw a detailed sketch with notes