Exam Flashcards
What is Forensic Science?
the application of a broad spectrum of science to answer questions relevant to the legal system. It involves the gathering, identification and interpretation of pieces of evidence that may be used in a criminal or civil lawsuit.
Forensis
Latin- before the forum
Forensic Science vs. CSI
CSI involves the on-site investigation of the physical scene of a crime
CSIs are usually civilians or police officers that have been trained for duty in crime scene units to document and record the crime scene and collect evidence
forensic specialists may be called in to assist under special circumstances
Forensic scientists generally perform their analyses in a controlled lab environment
Forensic Science Specialties
Pathology and Biology Odontology Physical Anthropology Criminalists Engineering Psychiatry and Behavioral Sciences Digital and Multimedia Sciences Jurisprudence Questions Documents Toxicology General
Anthropology
Forensic Anthropology is the application of physical anthropology to the legal process: the identification of skeletal, badly decomposed or otherwise unidentified human remains
Pathology
Forensic Pathologists are MDs trained in forensic pathology who work to determine the cause and manner of death
Cause of Death
Injury or disease that begins the train of events that ultimately leads to death, mechanism, and manner of death
Pneumonia
Gunshot wound
Drowning
Manner of Death
Natural- due to acute illness or chronic disease
Accident- non-natural death due to unintentional lethal event or action
Homicide- any death due to the action of another
Suicide- due to self-inflicted injury with intent to die
Undetermined- used when there is not enough information about the circumstances surrounding the death
Odontology
Deals with the handling, examination, and interpretation fo dental evidence
Most commonly involves the identification of individuals from dental records
Forensic Odontology uses dental records, including radiographs to compare antemortem and postmortem records to make an identification
Criminalistics
The forensic science of analyzing and interpreting evidence using the natural sciences
Criminalists analyze the physical evidence generated by crime scenes
Criminalists tend to specialize in one area of forensic analysis
They use physical evidence to create a link between the suspect and the victim
Serology
The analysis of body fluid evidence that includes bloodstains, semen stains, and saliva
DNA typing is possible with a sample of body fluid such as blood, saliva, or semen
Trace Evidence
The analysis of hairs, fibers, paint, glass, wood, and soil that are present at a crime scene
Helps to establish a relationship between the suspect and the victim
Ballistics
Criminalists can determine the kid of bullet used and whether it was fired from the gun used to commit the crime
Toolmark Analysis
Includes an object suspected of containing the impression of another object that served as a tool in the commission of a crime
Impression Evidence
The evaluation of impressions made by shoes, tires, depressions in soft soils, and all other forms of tracks and impressions
Drug Identification and Toxicology
The study of poisons and identification of drugs
Engineering
Forensic Engineers investigate the specific sequence of events in a case and search for reasons why a specific item failed to work as expected
Work with law enforcement to a variety of cases including: fire investigations, traffic accidents, patent disputes, wrongful injury claims
Behavioral Forensic Science: Forensic Psychiatrists and Psychologists
Both involve the interaction of mental health and the legal system. Both roles assess defendants to determine their competency to stand trial; aid family service workers in custody trials; and work with attorneys, defendants, and patients in the prison system. Both can diagnose and treat mental disorders. Both offer career paths for those with undergraduate and graduate degrees.
Forensic Psychiatrists
MD
Focuses on the biology of the brain as it applies to the CJS. The work of forensic psychiatry tends toward a heavy focus on science and forensic psychiatrists diagnose and treat mental disorders in the context of the CJS. Their work involves assessing clients, providing diagnoses, and prescribing medication.
Focuses on the medical aspects of mental health
Forensic Psychologists
Ph. D., Psy. D., or Ed. D
Examines how mental health conditions and disorders apply to the CJS. This involves determining trial competency for defendants, prosecutors, and witnesses; assessing the risk of inmates under consideration for release; and even aiding in jury selection. Psychologists are required to be licensed by the state but are not MDs and are not allowed to prescribe medication.
Focuses on social and behavioral elements of mental health care and how they affect the CJS
Computer (Digital) Forensics
The use of analytical and investigative techniques to identify, collect, examine and reserve evidence/information which is magnetically stored or encoded.
Combines elements of law and computer science to collect and analyze data from computer systems, networks, wireless communications, and storage devices in a way that is admissible as evidence in a court of law.
Entomology
Forensic Entomology is the use of insects and their arthropod relatives that inhabit decomposing remains to aid in legal investigations.
Most commonly employed in the estimation of the minimum post-mortem interval.
The body could not have been dead for less time than it would have taken insects to arrive at the corpse and develop.
What is Evidence?
“Anything that furnishes or tends to furnish proof; it can support OR reject the theory of the crime”
Must be relevant and reliable to be admitted into proceedings in a court of law
Relevance
Tendency of a given item of evidence to prove or disprove one of the legal elements of the case
Reliable
Consistently good in quality of performance; able to be trusted
Admissibility of Trial Information
Relies upon: prerequisite of sold supportive foundation for any offer of evidence; foundation consists of sufficiently supportive information presented to a judge that has potential to be true and aid a jury in a reasonable determination of whether it is indeed true.
Determined by the trial court’s application of the rules of evidence: evidentiary rules are exclusionary in nature- they serve to filter out information presented by either side that may be irrelevant to the factual and legal issues at hand or violate long-standing prohibitions such as those against the admissibility of hearsay or substantially prejudicial information.
Frye v. United States (1923)
Regarding the question of admissibility of polygraph tests as evidence
The court held that expert testimony must be based on scientific methods that are sufficiently established and accepted in the field in which it belongs
Daubert v. Merrell Dow Pharmaceuticals (1993)
Two minor children and their parents alleged their suit against Merrell Dow that the children’s serious birth defects had been caused by the mother’s prenatal ingestion of Bendectin, a prescription drug marketed by Merrell Dow.
The District Court granted the defendant summary judgement based on a well-credentialed expert’s affidavit concluding, upon reviewing the extensive published scientific literature on the subject, the maternal use of Bendectin has not been shown to be a risk factor for human birth defects.
The case was appealed and affirmed in the US Court of Appeals for the Ninth Circuit, based on the Federal Rules of Evidence.
The Daubert decision affirmed the role of the judge as gatekeeper in the admissibility of scientific evidence.
Daubert Case: In addition to the “general acceptance” criterion, in order to ensure that the evidence introduced is relevant and reliable, courts also examine the following questions:
Is the theory or technique invoked testable and has it been tested?
Has it been published in a peer-reviewed forum?
What is the known or potential error rate for a technique?
Forensic Evidence
Concerned with the linkage of persons, scenes and objects
Identification, collection and testing of crime scene evidence are the focus of forensic scientists
The goal is often to physically link the suspect to the crime scene, thereby providing inferential evidence of his/her commission or association with the crime
Forensic science data can be accepted as evidence of material fact once it survives the screening function
The Locard Exchange Principle
Whenever two objects come in contact, a mutual exchange of matter will take place between them
Circumstantial by Nature
Evidence in which an inference is required to connect it to a conclusion of fact
Direct Evidence
Evidence established without need for further inference
i.e. eyewitness testimony of shooting
Class and Individual Characteristics
Forensic evidence arrives in court in one of two basic forms: Class characteristics that do, inferentially, associate a particular individual with commission of a crime
Class characteristics have a high chance of belonging to some other item or person
With individual characteristics, the odds of the feature being repeated in the population is negligible
Four crime scenes are found within one crime scene
Physical scene left by perpetrator
Crime scene material collected and transported by crime scene personnel
Crime scene material tested by laboratory and results of such tests
Crime scene information allowed into evidence by court
What is Forensic Science?
The application of science to those criminal and civil laws that are enforced by police agencies in a CJS; uses scientific method
Locard’s Principles- CSI
When 2 or more items come in contact with an object or other person, a cross-transfer, or exchange of information will occur
For a CSI, this transfer becomes evidence
Locard strongly believed that every criminal can be connected to a crime, sometimes even by dust particles carried from the crime scene
First step of crime scene: Search
Purpose to obtain evidence
Any method of a search can be used, depending on the size, location, and complexity of the search
Systematic and thorough
Grid Search
People overlap line searches to form a grid
Quadrant/Zone Search
Most used method
For houses/buildings- break individual rooms into smaller sections
Strip/Line Search
Second most used method
In streets
People side-by-side and in a line, everyone takes a step and looks around before next step
Spiral Search
Used the least
More room for error especially when in wilderness
Scene Processing
Though every crime scene is different and techniques or application may vary, the process is the same
Scene Safety/Perimeter
Responsibility falls on the first responder
Protection of evidence
Prevents officers and others from aimlessly wandering and trampling evidence
Everyone is responsible for their own movements
Protective measures are decided on a case-by-case basis
When in doubt, go big
When is a crime scene destroyed?
The second the crime is committed: destroyed by the victim, offender, bystanders offering assistance, witnesses
Crime Scene Log Individual
One person who prevents people from coming in and out of the crime scene, especially those who aren’t supposed to be there
Secure and Isolate the Crime Scene
Two perimeters provide three areas of access
This keeps support police out of the actual scene and others at a safe distance
Hot Zone
Center of crime/where victim is
Inner Scene Perimeter
Keep distance between everyone on scene to avoid destruction of evidence
Outer Scene Perimeter
Where everyone else can be
Scene Sketch
Creates a mental picture of the scene for those not present
Depicts the overall layout of the scene
Make a simple line drawing of the crime scene on whatever paper you have: needs a North arrow and include where evidence is
Measurements can be placed on the sketch: i.e. how far away is the gun from the body?
Sketch (by hand) is turned into diagram (via computer)
Document Through Photographs
A picture is worth a thousand words
Takes the jury inside the scene
Photos are going to help you remember where you picked stuff up
Show the relationship of the scene to its surroundings
General to specific
Types of Pictures
Far
Medium
Close
Fingerprint Analysis
The two underlying premises of fingerprint ID are uniqueness and persistence (permanence)
No 2 people have exactly the same fingerprints, even identical twins with identical DNA
A person’s fingerprints remain essentially unchanged throughout their lifetime, though they do grow
Only first 2 of 3 levels of detail needed for comparison
Pattern Type
First level of detail
Arch
Loop
Whirl
Minutia or Ridge Characteristics
Second level of detail
Galton details: ridge endings, bifurcations, etc.
Ridge Characteristics
Third level of detail
Pore shapes
Ridge flow
Wipes
Putting blood from hand on wall
Swipes
Blood already on wall is smeared by hand
Cast Off
Blood pattern consistent with weapon hitting body, perpetrator’s arm being brought up then down to hit again
Arterial Spurting
Projected blood from injury to major artery
High Velocity
Blood coming out in mist
i.e. gunshot wound, especially to the head
Shooting Reconstruction
Uses lasers to demonstrate bullet path, captured on camera
Wooden dowels used if too many bullet holes for lasers
Blue Star
Replacement chemical for luminal
Used to locate blood that cannot be seen
State of Utah
Utilizes Medical Examiner
Mechanism of Death
The biochemical or physiologic abnormality resulting in death
Arrythmias of the heart, shock, or bleeding
Cardiac arrest
Respiratory arrest
Exsanguination
Shock
Gunshot wound to head: cause v. mechanism of death
Cause= gunshot wound Mechanism= specific injuries to the brain
