CSI introduction

Investigate

To make a systematic examination or to conduct an official inquiry

Crime

Act or commission of an act that is forbidden by a public law and that makes the offender liable to punishment by that law

Crime scene investigation (CSI

Process associated with the investigation of a criminal event, which involves a systematic process of documenting, collecting, preserving and interpreting physical evidence - scientific - 8 heads in a duffel bag

Trier of fact

the determination of guilt or innocence left up to the judge/magistrate or jury of peers

Criminalistics

The analysis of physical evidence

-Important to note that criminalistics and CSI are not the same

First tier of the investigation process is the first responder

• First Responder: typically the police officer who is dispatched to the initial scene

• The duty of the first responder is to secure the scene and begin securing and preserving the physical evidence

The second tier of the investigation process is the detective/ investigator

• This is a specialized police officer with significant experience in investigations

• The detective processes information given to him/her and determines if there needs ti be any additional investigation. He/she will also collect testimonial evidence

The third tier of the investigation process is the crime scene investigator/crime scene technician

• He or she has advanced training in documentation, collection, and preservation of physical evidence

• He or she processes the scene and transports the evidence into booking

The fourth tier involved in the investigation process is the criminalist

• Responsibilities of the criminalist include analyze and interpret the evidence using the latest scientific instrumentation

The fifth tier of the investigation process is considered the courts

• This process involves the prosecution, defense, judge/magistrate, and jury in determining if enough evidence was presented to show that a crime was committed

Objectives of Crime Scene Investigation

• Determine whether a crime has been committed

• Discovery and documentation of all facts

• Identify and eliminate suspects by collecting physical and testimonial evidence

• Locate and apprehend the perpetrator

• Maintain a proper chain of custody

• Effectively testify as a witness

• look to see if all elements of a crime are satisfied and get all the pieces of the puzzle together/ plus one theory

Questioning

• If you ask questions and they say something that seems unimportant to what you are asking it is important

• Listen to what they have to say

• Don’t go into things with a closed mind

Crime scene

anywhere that evidence may be located that will help explain the events; location at which the crime was committed

Primary scene

the first scene where evidence is located

Secondary scene

any subsequent scene to the primary

every crime scene is

unique and dynamic

Testimonial evidence

vocal statements that most commonly made by a person who is under oath

• Examples: witness statements, victim statements, and spontaneous utterance by suspects

• It is important to note that all testimonial evidence is considered to be a lie until corroborated by other physical evidence or testimonial

Real or physical evidence

any type of evidence with an objective existence- that is, anything with size, shape, and dimension

Examples: gases, fingerprints, glass, paint, hair, blood, soil, and drugs

Direct or circumstantial evidence

can be involved with either testimonial of physical evidence

• Direct evidence: proves a fact without the necessity of an inference or a presumption

• Circumstantial evidence: involves a series of facts, that although not the fact at issue, tend, through inference, to prove a fact at issue

Objectives of Crime Scene Investigators at the scene of a crime or incident

• Identify a suspect

• Place the suspect at the crime scene

• Reconstruct the events as they happened

Major Goals of a Crime Scene Search

1. Recognition and identification of physical evidence

2. Collection and proper preservation of the evidence

3. Reconstruction of the crime

4. To assist detectives in forming a theory about the crime

Locards Theory

Wherever he steps,, whatever he touches, whatever he leaves, even unconsciously, will serve as a silent witness against him. Not only his fingerprints or his footprints, but his hair, the fibers from his clothes, the glass he breaks that does not , the tool mark he leaves, the paint he scratches, the blood or semen he deposits or collects. All of these and more, bear mute witness against him. This is evidence that does not forget. It is not confused by the excitement of the moment. It is not absent because human witnesses are. It is factual evidence, physical evidence cannot be wrong, it cannot perjure itself, it cannot be wholly absent. Only human failure to find it, study and understand it, can diminish its value.

• It is also known as Gross theory

Physical evidence is valuable in many aspects

• Providing essential information on the facts of the case - the corpus delicti.

• Revealing the modus operandi (MO) - the preferred method of operation.

• Demonstrating linkages between the victim, suspects, locations, and objects.

• Proving or disproving witness statements.

• Identifying a suspect through DNA or other individualization.

• Classifying unknown substances.

• Reconstructing the crime scene - how a crime was committed.

• Developing investigative leads.

Four Major Factors that Determine the value of Physical Evidence

• REs of the witnesses COGNITION: The CSI must have the knowledge and understanding to recognize potential items of physical evidence located at the crime scene.

• Collection: Utilizing the appropriate skills and following accepted protocols to gathers and preserve the physical evidence.

• TESTING PROCEDURES: Application of acceptable scientific procedures to analyze the physical evidence.

• COURTROOM PRESENTATION: Qualification of the witnesses to provide objective reports on the forensic analysis of the evidence.

Crime Scene investigators

can also be referred to as evidence technicians, criminalistics officers, forensic investigators, of crime scene analysts. These professionals have a duty to complete the investigation of a crime scene by identifying and locating physical evidence, documenting the location and condition of that evidence, collecting and preserving the evidence for transportation to the crime laboratory and maintaining the chain of custody pf the physical evidence at the scene in order to preserve the integrity of the investigation.

EXPERT WITNESSES:

• The court considers that knowledge gained through education, training, and experience is sufficient grounds for qualification as an expert witness.

• Discrediting the chain of evidence, the scientists, or the science is known as the O.J. effect, named from the murder trial of O.J. Simpson in 1995, and has become a key defense technique.

The Judge

• Presiding over the hearing will render a decision on the “expert” status of witnesses. Once credentials have been established, the expert witness can provide opinions bases on the outcomes of examinations and the significance of the findings.

CHAIN OF CUSTODY

• The chain of custody usually refers to the documentation of the location of all physical evidence at all times. It is important for the CSI to stress the importance of the chain of custody for all items at the crime scene.

• Failure to maintain the Chain of Custody (Chair of Evidence) can result in the inadmissibility of evidence

Chain of Custody

Comprehensive documented history indicating the seizure, custody, transfer, analysis and deposition of evidence.

• Strict handling of evidence

• Chronologically and completely document every transaction of evidence.

• People vs. Julian, 41 NY2d

Chain of Custody and Admissibilitu of Evidence

important to note gap in chain of custody does not necessarily mean evidence will be inadmissible

• Admissibility of physical evidence is dependent upon being identifiable and unalterable

• People vs. Arthus, 99 AD2d 595

• Courts have classified physical evidence as fungible or non-fungible

Cain of Custody and Admissibility of Evidence

Summary of Admissibility Guidelines

• To assure admissibility of evidence, the prosecution must demonstrate:

• Identity of the evidence by one familiar with it.

• During any gap in the chain of custody no outside party could have caused a material change in the nature or condition of the evidence.

Overcoming Chain of Custody Problems

Complete custody documentation must be maintained once evidence is properly collected.

• Crime Scene Evidence Specialist is essential to chain of custody

• Fewer individuals involved, easier to demonstrate chain of custody.

• Maintain diligent procedures.

LEGAL ISSUES AND THE CRIME SCENE

1. Officers can enter a scene to search for victims and render aid in areas in which a victim could reasonably be found.

2. Responding officers may enter a scene to search for perpetrator(s) again only in areas where a suspect could be located.

3. While officers are legally in a location performing either of the two aforementioned actions, they may seize items of evidentiary nature that are in plain view, however, this should only occur in exigent circumstances.

   • Not only can physical evidence that was obtained illegally not be admitted into court, but also any subsequent information that may be derived from the excluded physical evidence is referred to as fruit of the poisonous tree.

Search Warrants:

• The Fourth Amendment - protects against unreasonable search and seizure

• Jurisdictional requirements - they can vary, and investigators should obtain search warrants uf consent to search cannot be obtained from someone who is legally authorized to permit the search.

CLASS vs. INDIVIDUAL CHARACTERISTICS

• CLASS,

  -Physical evidence cannot always be related to a common origin with a high degree of certainty, therefore, when it can be associated only with a group and never a single source, it is said to be class evidence

  • INDIVIDUAL CHARACTERISTICS - are distinct differences in the physical evidence that allow it to be associated with a single source and allow the examiner to determine the uniqueness of any single object or piece of evidence

CONTROLS

Quality control practices are essential for maintaining the integrity of testing and results in a scientific environment. Control samples should be obtained when required.

Things Mullen says

• He says you can do this because he can.

• When there is a case he always asks if it is the big 8 heads in a duffel bag case but he will go if it is not a big case.

Locard's Exchange Principle:

Whenever two objects come contact with one another, there is a cross transfer of evidence that occurs.

• This process stated that every crime stated that every crime scene could be connectedto a criminal, witness, and victim, and vice versa

3X + 8 = 17

The Essence of Police Work (Problem Solving)

work with what you know to find out what you don’t know - isolate the unknown