Techniques and Procedures
What is the purpose of the chain of custody in crime scene investigation?
The chain of custody is a documented record of individuals who had control of the evidence, ensuring its integrity and admissibility in court.
In the context of crime scene investigation, what significant role did the O.J. Simpson case play?
The O.J. Simpson case highlighted challenges with evidence collection, forensic analysis, and the impact of celebrity status on legal proceedings.
Differentiate between primary and secondary crime scenes
Primary Scene:where the actual criminal activity took place. Investigators initially concentrate their efforts on the primary crime scene to establish the sequence of events, identify potential suspects, and collect evidence that directly connects to the crime.
Secondary Scene: A place where evidence from the primary crime scene may have been transferred, left, or deposited. Investigating the secondary crime scene is important for understanding the movement of individuals involved in the crime, identifying potential accomplices, and establishing the connection between the primary and secondary locations.
Provide examples of where to find trace evidence.
Clothing (fibers), footwear (dust, soil, debris, vegetation, bloodstain), body (GSR, hair) tools/weapons (metal shavings, paint)
Explain the difference between latent and patent fingerprints.
Latent fingerprints are invisible and require development techniques, while patent fingerprints are visible and do not need enhancement.
What are the steps for preserving a footprint?
Protect the impression, photograph, cast with dental stone/dust
Explain the impact of the Daubert standard on the admissibility of scientific evidence in court.
The Daubert standard establishes criteria for the admissibility of expert scientific testimony, ensuring reliability and relevance.
What challenges do investigators face when dealing with outdoor crime scenes?
Challenges include exposure to weather elements, difficulty preserving evidence integrity, and the potential for a larger search area.
What is the most sought out physical evidence in arson?
ignitable fluids or accelerants,
Define "rigor mortis" and its relevance to crime scene investigation
Rigor mortis is the stiffening of muscles after death, and its progression can help establish the time of death
What information is required to establish chain of custody?
Name and/or initials of individual collecting the evidence and each person having custody of it
Date the items were collected
Agency, case number, and type of crime
Voucher or property clerk number
Victim's or suspect's name
Storage location
Brief description of the item
Name two landmark court cases that significantly influenced the admissibility of forensic evidence.
Daubert v. Merrell Dow Pharmaceuticals and Frye v. United States.
What is the purpose of using luminol at a crime scene, and what does it detect?
Luminol detects the presence of blood, even in trace amounts, by producing a blue glow.
How does class evidence differ from individual evidence
Class evidence narrows to a group, while individual narrows to a single source.
Discuss the importance of the "Locard Exchange Principle" in forensic science.
The Locard Exchange Principle states that every contact leaves a trace, emphasizing the transfer of evidence between individuals and objects at a crime scene.
What role does the Crime Scene Sketch play in documenting evidence and the scene itself?
The Crime Scene Sketch provides a visual representation of the scene, including the location of evidence, which aids in reconstruction and analysis
What is required for a photograph to be admissible in court?
The investigator must be able to testify that it accurately depicts the area shown.
To be accurate, it must represent the subject matter properly in terms of color, scale, and form. Photographs must be in focus and show the relationships and distance between objects.
Explain the challenges associated with processing crime scenes involving arson.
Arson scenes are challenging due to the destruction of evidence by fire, requiring specialized techniques for identification and analysis
What is the role of forensic entomology in crime scene investigation.
Forensic entomology uses insect evidence to estimate the time of death, location of a body, and other aspects of a crime scene.
What is the role of forensic anthropology in crime scene investigations?
Forensic anthropology involves the analysis of skeletal remains to determine identity
What type of packaging is used for volatile liquids?
A clean metal paint can
What is the difference between expert witness testimony and non expert witness testimony?
An expert witness is someone who has specialized knowledge, skill, experience, training, or education in a particular field relevant to the case.
They're allowed to provide opinions or interpretations based on their expertise. They can draw conclusions and offer insights that non-experts would not be qualified to provide.
When encountering a crime scene with multiple victims, how does the approach to evidence collection and documentation differ, and what challenges might investigators face?
Challenges include the potential for cross-contamination. The approach involves meticulous documentation and separate processing areas for each victim.
What fingerprint technique is used on porous surfaces and reacts with amino acids to form a purple-colored compound called "Ruhemann's Purple"?
Ninhydrin Solution
What does the acronym CODIS stand for, and how is it used in criminal investigations?
Combined DNA Index System; it helps link DNA evidence from crime scenes.