Criminal Investigations - Chapter 1 Notes
Wise Words
Quote: “Nothing matters but the facts. Without them, the science of criminal investigation is nothing more than a guessing game.” — Blake Edwards
Crazy Facts
There are approximately 12{,}000{,}000 crimes committed in the United States every single year.
There are over 100{,}000 rapes in the United States every single year.
Every year, one out of every five people is a victim of a crime in the United States.
Example/non-statistical impact: mother and five children died in a house fire in New Jersey after nailing their doors shut as they feared being crime victims.
One in five teenagers has been the victim of a violent crime and are twice as likely as any other group to be shot, stabbed, or sexually assaulted.
Crime and the Investigator
Crime is a major concern in the U.S. and is the number one fear for many people as potential victims.
Approximately 2.5\,\text{million} people over age 12 are victimized by a violent crime annually.
The National Crime Survey reports that less than half of serious crime is reported to authorities.
Key question: Why don’t people report crime?
Crime
Questions raised:
Are all crimes solved?
Are all crimes solvable?
What is a Part One Crime?
How are crimes solved?
Note: the slide content shows a partially obscured or garbled cross-out related to crime scene text (e.g., "NOT CRO" / "RIME SCE"). The intended takeaway is the recognition of crime scene boundaries and proper handling, i.e., Do Not Cross barriers.
Criminal Investigations (Definition)
A criminal investigation is the process of discovering, collecting, preparing, identifying, and presenting evidence to determine what happened and who is responsible.
Key Terms
Crime: an act or violation of law.
Felony / Misdemeanor
Criminal statute: a legislative act relating to crime/punishment.
Criminal Intent: knowing the act is illegal.
Elements of a crime / corpus delicti.
Modus operandi (MO): how a criminal operates.
Deductive and Inductive Reasoning
Deductive reasoning: reconstructive process where specific pieces of evidence establish proof of guilt.
Inductive reasoning: move from the general to the specific by gathering facts.
Outcome-based consideration: what is best outcome given the facts.
Investigative Process (Stages)
Initial Report
Initial Investigation
Incident Review
Follow-Up Investigation
Case Preparation / Approval
Prosecution
Conclusion
Note: Slide includes the word "PROTECT" and fragments like "CAR CAGO POL" which likely reflect mnemonic prompts about protecting the scene; focus on the core stages above.
Protecting the Crime Scene
Locard’s Principle of Exchange: material transfer occurs when objects come into contact.
Transfer of material from one object to another is central to crime scene evidence.
Critical to the investigation: scene protection and evidence integrity.
Lock down the scene; manage hazards at outdoor scenes.
Keep perimeter large, then shrink as needed.
Assign duties to all officers involved.
KEEP A LOG of all actions and movements at the scene.
Preliminary Investigation
Questioning everyone: interview potential witnesses, suspects, and bystanders.
Canvass the area for additional information.
Crime scene sketching and documentation.
Searching for evidence.
Processing physical evidence and performing field tests.
Recording all statements and observations.
Importance of Forensic Evidence
Since the Miranda decision, forensic evidence has become increasingly important.
Forensic evidence has many good points; physical evidence usually speaks for itself (not always).
Forensic Evidence Statistics (Jury Expectations)
46\% of juries expect to see some kind of forensic evidence.
22\% expect to see DNA evidence in every case.
36\% expect fingerprint evidence in every case.
32\% expect firearms-related evidence in every case.
Investigative Philosophy
Principle: Prove the suspect innocent! (A counterintuitive but emphasized idea in some training materials.)
Investigative Philosophy (Remove the Means, Motive, Forensics)
Remove the Means.
Remove the Motive.
Remove Forensics.
Confirm Alibi.
Move on to the next potential lead.
Goals of an Investigation
More than just identifying and arresting a suspect.
Goals:
1) Crime detection / determine if a crime was committed.
2) Locating, recording, and processing evidence.
3) Locating and identifying suspects / making arrests.
4) Recovering stolen property.
5) Presenting the best case to prosecution.
A Successful Investigation
A successful investigation follows a logical sequence.
All evidence is legally obtained.
All witnesses are effectively interviewed.
All suspects are legally and effectively interrogated.
All leads are thoroughly developed.
All details are accurately and completely recorded and reported.
Successful testimony in court.
The Role of the Investigator
To meet goals/objectives and conduct a successful investigation, the investigator must:
Be creative
Have ethics
Have good morals
Understand human nature
Possess strong communication skills
Respect the law and the Constitution
Investigative Ethics
What are ethics?
Professionalization of criminal investigations.
Causes of unethical behavior.
Reminder: WE ARE OBJECTIVE FACT FINDERS!
Desirable Traits of the Investigator
Imagination
Intuition
Observation skills
Organizational ability
Legal knowledge
Cultural knowledge
Being relentless
Computer-Aided Investigations
CompStat—started by William Bratton.
Four Principles:
Accurate and timely intelligence
Rapid deployment of resources
Effective tactics
Relentless follow-up / assessment
Crime Mapping
Crime mapping uses Geographic Information Systems (GIS) and geographic profiling.
Hot spot policing.
New trend in policing.
Data mining.
Investigations and Relationships
Interactions with:
Uniformed patrol
Dispatchers
Prosecutors
Defense counsel
Community corrections
Social services
Physicians / Coroners / Medical Examiners (ME)
Investigations and Interrelationships (continued)
Forensic crime laboratories.
Citizens, witnesses, victims.
Nothing gets done alone.
Dealing with the Media
Do not contact journalists unless it is your responsibility.
Be courteous; keep the public and media away from the crime scene.
Do not say "no comment"; avoid misquotations and statements out of context.
If subject to press coverage, have a Public Information Officer (PIO) speak on your behalf.
Question of truthfulness in communications remains.
How Can the Media Help?
Media channels can disseminate information and assist in investigations when used correctly (e.g., NEL News, Channel News, etc.).
Investigative Checklist
Information disseminated.
Communications Center notifications.
Contact with outside agencies.
Crime analysis maps.
Composite drawings.
Video recording and playback.
Tags and installation of video surveillance.
Canvass operations.
Ram tags (search and tagging of items).
Media releases.
Predictive policing integration.
Surveillance and directed patrols.
Identification of patterns and crime alerts.
Solvability Checklist
Follow-up interviews with victims/witnesses.
Narcotics involvement.
Stings.
Informants.
Note: Other solvability factors (items 1–16) are not listed here but are implied in comprehensive investigations.