1. Science of Crime Scenes
Chapter 4.0
Science of Crime Scenes

2. General Crime Scene Procedure
All crime scene procedures are based around the three R’s:
Recognize
Recover
Record
The three R’s may seem simplistic
They are methods by which the maximum amount of information may be extracted from any crime scene by a well-trained experienced crime scene team
Science of Crime Scenes

3. Science of Crime Scenes
Recognize
Establish the dimensions and identify potential safety and health hazards
Establish dimensions
Locate focal point
Check for “secondary” scene
Identify safety hazards
Biohazards, power, weapons, chemical hazards, traps
Contamination
Victim assistance
Communicate hazards to other responders
Science of Crime Scenes

4. Science of Crime Scenes
Recognize
Establish Security
Establish boundaries, physical barriers, entry/exit paths
Restrict access
Log participants
Exclude unnecessary people
Protect evidence
Plan and communicate
Determine type of investigation
Gather data and intelligence
Address legal issues
Determine processing priority
Define resources (current and future)
Secure areas
Science of Crime Scenes

5. Science of Crime Scenes
Recognize
Conduct a primary survey
Identify evidence
Document
Determine processing list for evidence collection
Science of Crime Scenes

6. Science of Crime Scenes
Record
Document and process the scene
Photography
Notes
Observations
Sketches
Task assignment
Conduct a secondary survey
Determine search pattern
Prioritize search areas
Consider environmental factors
Science of Crime Scenes

7. Science of Crime Scenes
Recover
Recover and preserve evidence
Collect evidence
Science of Crime Scenes

8. Can you “freeze” a crime scene?
It’s not easy
It can’t be done
The best a CSI and his team can do is to minimize the loss of physical evidence and recover the maximum amount of pertinent physical evidence.
Science of Crime Scenes

9. Garbage Truck Forensics
Fear is not a good strategy
Yet fear of missing evidence leads some police agencies or CSIs to collect every possible item of potential evidence at a crime scene
They “dump” all of this evidence at the laboratory, thinking, “They’re the smart scientists; they can sort out the important stuff.”
“Garbage truck forensics”
This type of unconsidered evidence submission creates numerous problems in the criminal justice system
Science of Crime Scenes

10. Science of Crime Scenes
Opportunity Costs
An opportunity cost is the cost of doing something measured in terms of the value of not doing the next best thing (the second best choice)
In economics, it is characterized as the essential relationship between scarcity and choice
If someone wanted to go to two sporting events that were scheduled for the same time, they can only go to one. The opportunity cost of going to the basketball game would be the cost of not going to the hockey game.
Science of Crime Scenes

11. Science of Crime Scenes
Opportunity Costs
Likewise, if a “garbage truck” of evidence is submitted to the laboratory, it will take the scientists that much longer to sort through all of the items, process them, and then choose which ones to analyze
The time they spend doing this keeps them from working other items in other cases, possibly ones that were submitted by the very same CSI
Therefore, the opportunity cost of submitting everything and hoping the laboratory will sort it out is increasing the time to process the next case submitted
Complaints may be voiced about how slow the laboratory is without realizing the CSIs and officers in the field are directly contributing to the wait
Science of Crime Scenes

12. Science of Crime Scenes
Intelligence, not fear
This reinforces the importance that systematic methods must be used to recognize and recover physical evidence that is relevant to the investigation while excluding unnecessary material.
Science of Crime Scenes