Survey to forensics-cjfs 1500 PDF

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these notes are talking about the basics of forensics. manners of death, causes of death, etc....

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Survey to forensics The scientific method and its application to forensic science The scientific method is an important component of the forensic science Forensic science is a science Important for the crime scene reconstruction A logical and productive approach for crime scene investigations Forensic science is multi disciplinary Forensic pathology Pathology is a specialty area of medicine-the study of diseases and bodily changes caused by diseases Forensic pathology determines the cause of death(the medical reason why a person died; asphyxiation Forensic pathology determine the manner of death circumstances causing death and homicide Manners of death Homicide Natural cause Suicide Accidental Unknown Causes of death Asphyxiation Gunshot wound Autoposy- the medical dissection and examination of a body Death investigators- assist in determining cause/manner of death Certification: ABMDI- American board of medicolegal death investogators Rigor mortis- stiffness of death Algor mortis-coldness of death Livor mortis- blueish color of death Forensic entomology Entomology- a branch of biology devoted to the study of insects Forensic entomologists use insects as investigative aids With knowledge of the life cycle of insects they examine insects, larvae, pupae associated with a corpus, and accounting for existing environmental factors,

they can estimate the time of death Forensic odontontology Odontology- study of the physiology, anatomy, and pathology of teeth Forensic odontologists perform two types of analyses involving the human dentition Identify human remains by comparing premortem and postmortem dental xrays Bite marks comparisons (crime scene marks to know bite marks) Forensic anthropology Anthropology- study of humanity and its evolution Physical anthropology- science of the human skeleton and how it has evolved over time Determine weather remains are human or animal Reconstruct the skeleton from remains Provide an estimate of age, stature, and gender Sometimes determine racial origin detect skeletal normalities and any trauma Provide information about the cause of death Assist in forensic sculpture Forensic toxicology Toxicology- study of chemicals and their effects Forensic toxicology is the study poisons/drugs In the body and their effects in legal context Must determine both presence and amounts of extraneous materials in the body Assist the medical examiners in determining the cause of death May be involved in determining ethanol levels in blood and breath samples Forensic psychiatry and psychology Psychiatry- branch of medicine concerning the diagnosis, treatment, and prevention of mental illness Psychology- study of the mind and behavior of humans Forensic psychiatrists and psychologist evaluate offenders for civil and criminal competence and may be involved in offensive treatment programs A few specialize in “filing” of criminal cases, primarily murderers and serial rapist Motis operandi Forensic engineering; Involved int he investigation of transportation related accidents, material failures, and structural failures Forensic computer science;

Use information located on computers and other electronic devices investigation aids Find hidden or information to determine if internet based is being committed Physical evidence- any object hat can establish that a crime has been committed or can link a crime and its victims or its perpetrator. Legrand case How is it produced Changes induced at a scene: – Virtually any object or observed condition may prove to be useful physical evidence – Physical evidence typically results from a change induced at the crime scene – The deposition of something not previously part of a crime scene or an alteration of something that was there Imprints or indentation – An imprint is a two dimensional mark or pattern left by an object through contact with another object – And indentation is a three dimensional mark or pattern left in a soft surface through contact with another object Striations – Striation marks or scratches left on a surface by an object in contact and in motion along that surface – Important in reconstruction of events – Combination of macroscopic and microscopic striations can be used to individualize physical evidence Damage – Physical evidence can be produced as a result of damage, tearing forces, breakage, cuts, and other processes – Many of these processes produce unique two and three dimensional surfaces leading to individualization of the evidence Exchange of material upon contact – Physical evidence can be generated by the transfer of material during contact – The locard exchange principle:n when two surfaces come into contact, there is a mutual exchange of material – The locard exchange principle is an important guiding axiom in the forensic sciences Deposited evidence – Physical evidence can be generated in non contact situations – Physical evidence such as pollen, hair, or fibers, may settle onto a surface – Physical evidence such as blood splatter may be deposited onto a surface as a result of physical force projecting blood droplets though the air Providing investigative leads ● Modus operandi

– Physical evidence examination can provide insight into the perpetrators modus operandi – MO refers to the perpetrators method of operation – The habits and patterns of criminal offender – Information about the mo may help to connect seemingly unrelated cases Computer database – three major computer databases help to provide investigative leads – AFIS: automated finger print identification system – CODIS: combined DNA indexing system – NIBIN: national integrated ballistics information network Establishing linkage – Linkaages are a connection or relationships between any or all of the following: objects, persons, scenes, instruments – Examples include: paint chips on a victims clothing in a hit and run case – Linkages based on two way transfers provide a much stronger evidence of association Establishing exclusions – Exclusions are just as important as inclusions – An exclusion means that the questioned item could not have came from a known item of evidence – If a paint chip from a hit and run does not match a suspects vehicle, the vehicle may be excluded as. Source of that evidence Supporting or disproving statements – One of the most useful applications of physical evidence is to corroborate statements – May play a critical role in refuting or corroborating an alibi or making a witness more believable – In the corroborative role, physical evidence enhances the credibility of an individual Identification of persons – In almost every type of case, there is a need ton ambiguously identify individuals – Many types of physical evidence can be helpful in this role: fingerprints, biological material, and dental information Identification of substances or materials – Showing that an item of evidence falls into particular class materials – If not cruel to solving a crime, critical to proving that a crime has been committed [. Recognition – The first step is to recognition that an object may be useful as physical evidence – What is or is not evidence depends on many factors

– Education, training, and experience are all important in recognizing evidence. 2. documentation – Proper and complete documentation is needed to establish the legal and scientific requirements for the chain of custody – Chain of custody- establishes where evidence has been and who handled the evidence – Every item offered as evidence in a court of law must be shown to be exactly the same as the object collected from individuals or scenes 3. Collection, packaging, and preservation – Evidence must be collected, properly packaged, and preserved for subsequent analysis – An essential consideration are control and comparison specimens – Control specimens may include blanks, known, and or alibi samples – A comparison specimen is used for comparison to evidentiary items 4.laboratory analysis – Lab analyses have one or more of the following objectives: identification, individualization, or reconstruction – Individualization may involve a comparison between a questioned specimen and a known specimen 5. Reporting and testimony – Forensic scientists convey their results in the form of a laboratory report – The laboratory reports must be clear, informative, and understandable. – Court testimony represents the final step in the physical evidence process – Forensic science may be qualified as expert witnesses based on education, training, or experience in their specialty area People have tended to live in close proximity and form societies for economic and security reasons Societies require a mechanism to deal with and to settle disputes Development of rules of conduct is one of the most important functions of society If a crime has been committed an investigation is open If a crime scene is established, the scene will be processed and physical evidence collected for lab analysis A suspect may be arrested for a crime if the police have probable cause Probable cause- legal standard that indicates there is sufficient evidence to convince a reasonable person that a person may be guilty Onc a suspect is identified, it is possible to seek a court order to obtain evidence from that individual for laboratory analysis...