2What is Forensic Science? Forensic comes from the Latin word forensis.Meaning - for public discussion or debate.Any science, used for the purposes of the law, is a forensic science.
3Forensic Scientists Television enhances the image of forensic science. Forensic scientists are not involved in all aspects of criminal cases.Goal - use all available scientific information to determine the facts &, subsequently, the truth.
4Forensic Scientists Scientific facts Based on investigation, not circumstantial evidence or the sometimes unreliable testimony of witnesses.Forensic scientists can prove the existence of a crime or make connections to a crime.
5Works Closely With State & Local Police & Sheriff Prosecuting and Defense AttorneysImmigration workersCrime scene investigatorsDEA – Drug Enforcement AgencyCIA – Central Intelligence AgencyFBI – Federal Bureau of Investigation
7Locard Exchange Principle Locard: director of the very first crime laboratory in Lyon, France.Principle states that "with contact between two items, there will be an exchangePerpetrator(s) of a crime comes into contact with the scene, they will both bring something into the scene and leave with something from the scene.Every contact leaves a trace.
9Firearms and Tool Marks Matching bullets to the gun that fired them.Tool Marks: ID characteristics between tools and the object it was used onPry bar and door with matching imprintsExplosives and imprint evidence.
10Firearms Gunshot residue particle analysis pertains to: Identification of bullet holesEstimation of range of fireLinking the suspect with the firing of a gun-in-question
11Forensic ProfilingSpecially trained psychiatrist or investigator can examine crime scenes to develop a personality profile of the offender.SexAgeOccupationLifestyle
12Document ExaminationThis discipline involves relationships that between document and inscription and how it relates to a person or sequence of events.ForgeryCounterfeitingHandwriting analysis.
13Document Investigation Document examination case fall into the "white-collar crime" categoryInclude identity theft, forgery, counterfeiting, fraud,Questioned documents are often important in so many different contexts and for so many different purposes.May commit murder and forge a suicide noteDocument being produced directly as a part of a crime
14Autopsy Post mortem exam determines: Manner of Death Method of Death Time of DeathPlace of Death
15Death That Must be Reported & Investigated Sudden or unexpectedSuspicious circumstancesResult of an injury of AccidentNatural death – disease or old age;Unnatural death – unexpected or unnatural causes
16Other Reasons for Autopsy Diagnosis DiseaseEvaluate possible public health issueFor example, the diagnosis of Alzheimer’s disease can only be confirmed upon autopsy
17Autopsy Process Includes external exam and photos Tattoos, Scars, Birthmarks, etc.Followed by extensive internal exam:Organs are removed, weighed and examinedTissues and fluids are analyzed for abnormalities & presence of drugs
19Medical ExaminerHas the legal authority to order an autopsy without the consent of the deceased person’s next of kin.If not ordered by Medical Examiner, MUST have permission from next of kin.
20DNA Typing What is DNA? Nucleus of cells contain RNA/DNA DNA has deoxyribonucleic acid.Nucleus has 23 pairs of chromosomes made up of DNAIn each pair, one chromosome from sperm, one from egg
21DNA TypingDeoxyribonucleic acid (DNA) is a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms and some viruses.The main role of DNA molecules is the long-term storage of information.
22DNA Typing What makes DNA individual? Four chemicals: Adenine Guanine CytosineThymine.
23DNA TypingDNA is often compared to a set of blueprints or a recipe, or a codeContains the instructions needed to construct other components of cells, such as proteins and RNA molecules.
25DNA Typing Such examination can establish whether a given strand is a strand of mammalian hair (vs. a synthetic or natural fiber),is a strand of human hairIs from the head or another region (pubic)Was a living, growing hair at the time it was separatedCame from a particular race of persons
26DNA Typing Chemical strung together = DNA code. DNA varies from individual to individualCan link a strand of DNA to a given individual.
27DNA Typing Where DNA is Found at the crime scene Specimens – blood, hair, bloodstained clothingProvides powerfully compelling evidenceLook in the Bathroom
28Forensic Anthropology Examination of Skeletal Remains Total Bones in body, 206, Missing Bones?Man 12 lbsWomen 10 lbsGender Male or Female: Pelvic GirthRace: To Some ExtentHeight: Ratio of Length of Long Bones to Height
29Forensic Anthropology Age at Time of Death: Size of Bones, Closure of EpiphysisCause of Death or Lifestyle: Wear and Tear, Disease Processes (arthritis, fractures)How a person lived;Debilitating illnesses (rickets, polio, healed fractures);Right or left handednessClues to occupation
30Odontology Examination of Teeth No other body part lasts longerIn fires, often the only thing remainingNo two people have identical teethDental records are needed to compare to the evidenceTeeth can determine a subject’s age
31Odontology WEST WARWICK, R.I., Feb 22, 2003 Fire investigators have recovered the remains of 96 victims of a Rhode Island nightclub and were working with forensic pathologists to aid identification efforts,9 of the victims had been identified so far through dental records.
34Blood - Serology Blood type – 4 types O, A, B, AB Rh Factor Female cells have Barr Body
35Blood Groups Blood Group Antigens Antibodies Can Give To Can Receive FromABA & BNoneAB, A, B, OABA & ABA & OB & ABB & OO
36BloodKastte - Meyer Test can determine if substance (stains) is really bloodPrecipiton Test determines if it is animal or human bloodDetermine gender from blood evidence – female cells have Barr body
37Determining Time of Death Rigor Mortis Begins 3 hours after death in face & eyelid musclesTakes 12 hours to affect entire bodyProcess reverses after 36 hours.Rigor Mortis –Nysten’s Law: Rigor mortis affects first the muscle of the head and spreads toward the feet.
38Determining Time of Death Lividity - Hypostasis Visible 30 – 60 minutes after deathRed cells settle & skin below turns redAfter 6 – 10 hours, color becomes permanent
39Determining Time of Death Body Temperature Falls at the rate of 1 degree per hourObesity and warm environment slows coolingNone of these are totally reliable and can be manipulated
40Forensic Entomologists Forensic entomologists work in classrooms, research labs & in the field.Practice of studying insects has existed for centuries, but there are so many areas of the field that remain largely untapped and promising.If body has been movedHow long the body has been there
42Eyewitness AccountsIt used to be thought that memories were kind of like video tapes, but we now understand that all memories are reconstructions of events.Memory is very plastic and malleableMemories are often manipulated and greatly affected by our emotional state, personal prejudices and biases.