Anth345 "Forensic Science" Exam 1 Notes
Anth345 "Forensic Science" Exam 1 Notes Anth345
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Date Created: 01/24/16
Chapter 1: Introduction ▯ Definition and Scope of Forensic Science ▯ Forensic Science applies the knowledge and technology of science to the definition and enforcement of such laws The most common definition: Forensic science is the application of science to the criminal and civil laws that are enforced by police agencies in a criminal justice system The diversity of professions practicing forensic science is illustrated by the eleven sections of the American Academy of Forensic Science them being: o Criminalistics o Digital and Multimedia Sciences o Engineering Science o General o Jurisprudence (The theory or philosophy of law) o Odontology (The scientific study of the structure and diseases of teeth) o Pathology/Biology (the science of the causes and effects of disease) o Physical Anthropology o Psychiatry/Behavioral Science o Questioned Documents o Toxicology (Branch of science concerned with the nature, effect and direction of poisons) “CSI Effect” o Television shows such as CSI have increased the public’s awareness of the use of science in criminal and civil investigations however, they have also posed unrealistic expectations of forensic science. o In these shows the CSI team collects evidence at the crime scene, processes all evidence, questions witnesses, interrogates suspects, carries out search warrants, and testify in court. In the real world however these types of things can take days, weeks, months and even years o This false image is significantly responsible for the public’s high interest in and expectations of DNA evidence ▯ ▯ History and Development of Forensic Science ▯ Literary Roots o Today many believe that Sir Arthur Conan Doyle had a considerable influence on popularizing scientific crimedetection methods through his fictional character as Sherlock Holmes First applied the newly developing principles of serology, fingerprinting, firearm identification, and questioned document examination long before their value was first recognized and accepted by reallife criminal investigators ▯ ▯ Important Contributors to Forensic Science ▯ Mathieu Orfila o Considered the “father of Toxicology”. o Published the first scientific treatise on the detection of poisons and their effects on animals o Alphonse Bertillon o Devised the first scientific system of personal identification o Began to develop the science of Anthropometry, a systematic procedure of taking a series of body measurements as a means of distinguishing one individual from another o Anthropometry was eventually replaced with fingerprinting in the early 1900s o Francis Galton o Undertook the first definitive study of fingerprints and developed a methodology of classifying them for filing o Leone Lattes o Karl Landsteiner discovered blood can be grouped into different categories (A, B, AB, O). o The possibility that blood grouping could be a useful characteristic for the identification of an individual intrigued Dr. Lattes, and he devised a relatively simple procedure for determining the blood group of a dried blood stain ▯ Calvin Goddard o Refined the techniques of such an examination to determine whether a particular gun has fired a bullet by comparing the bullet with one that has been testfired from the suspect’s weapon using the comparison microscope o Albert S. Osborn o Development of the fundamental principles of document examination and was responsible for the acceptance of documents as scientific evidence by the courts o Walter C. McCrone o Dr. McCrone’s career paralleled startling advances in sophisticated analytical technology (advancements in microscopes) o Hans Gross o Wrote the first treatise describing the application of scientific disciplines to the field of criminal investigation o Edmond Locard o Demonstrated how the principles enunciated by Gross could be incorporated within a workable crime laboratory o Locard believed that when a person comes in contact with an object or person, a crosstransfer of materials occurs (Locard’s exchange principle) o The perpetrator of a crime will bring something into the crime scene and leave with something from it, and that both can be used as forensic evidence o Locard maintained that every criminal can be connected to a crime by dust particles carried from the crime scene o ▯ ▯ Crime Laboratories ▯ Crime Labs in the United States o The oldest forensic laboratory in the United States is that of the Los Angeles Police Department created by August Vollmer o California has numerous federal, state, county, and city crime laboratories, many of which operate independently International Crime Labs o Great Britain had developed a national system of regional laboratories under the direction of the government’s Home Office o In Canada, forensic services are provided by three government funded institutes: Six Royal Canadian Mounted Police regional laboratories The Centre of Forensic Sciences in Toronto The Institute of Legal Medicine and Police Science in Montreal ▯ ▯ Organization of a Crime Laboratory ▯ The Growth of Crime Laboratories o Supreme Court decisions in the 1960s were responsible for greater police emphasis on securing scientifically evaluated evidence o Successful prosecution of criminal cases requires a thorough and professional police investigation, frequently incorporating the skills of forensic science experts. o Coinciding with changing judicial requirements has been the staggering increase in crime rates in the United States over the past forty years o There is, however, one important exception to this observation: drugrelated arrests All illicitdrug seizures must be sent to a forensic laboratory for confirmatory chemical analysis before the case can be adjudicated Drug abuse has accelerated to nearly uncontrollable levels and has resulted in crime laboratories being inundated with drug specimens Future Challenges o In coming years an estimated ten thousand forensic scientists will be added to the rolls of both public and private forensic laboratories to process crimescene evidence for DNA and to acquire DNA profiles, as mandated by state laws from the hundreds of thousands of individuals convicted of crimes ▯ ▯ Types of Crime Laboratories ▯ Federal Crime Laboratories o The federal government has no single law enforcement or investigative agency with unlimited jurisdiction o Four major federal crime laboratories have been created to help investigate and enforce criminal laws that extent beyond the jurisdictional boundaries of state and local forces The FBI maintains the largest crime laboratory in the world Ultramodern facility that houses the FBI’s forensic science services is located in Quantico, Virginia The Drug Enforcement Administration laboratories analyze drugs seized in violation of federal laws regulating the production, sale, and transportation of drugs The laboratories of the Bureau of Alcohol, Tobacco, Firearms and Explosives analyze alcoholic beverages and documents relating to alcohol and firearm excise tax law enforcement and examine weapons, explosive devices, and related evidence to enforce the Gun Control Act of 1968 The U.S. Postal Inspection Service maintains laboratories concerned with criminal investigations relating to the postal service State and Local Crime Laboratories o Local laboratories provide services to county and municipal agencies o Generally these facilities operate independently of the state crime laboratory and are financed directly by local government ▯ ▯ Services of the Crime Laboratory ▯ Basic Services Provided by FullService Crime Laboratories o Physical Science Unit Applies principles and techniques of chemistry, physics, and geology to the identification and comparison of crimescene evidence It is staffed by criminalists who have the expertise to use chemical tests and modern analytical instrumentation to examine items as diverse as drugs, glass, paint, explosives, and soil o Biology Unit Staffed with biologists and biochemists who identify and perform DNA profiling on dried bloodstains and other bodily fluids, compare hairs and fibers and identify and compare botanical materials such as wood and plants o Firearms Unit Examines firearms, discharged bullets, cartridge cases, shotgun shells, and ammunition of all types. o Document Examination Unit Studies the handwriting and typewriting on questioned documents to ascertain authenticity and/or source Analyzing paper and ink and examining indented writings, obliterations, erasures, and burned or charred documents o Photography Unit Examines and records physical evidence. Its procedures may require the use of highly specialized photographic techniques, such as digital imaging, infrared, ultraviolet, and xray photography ▯ ▯ Optional Services Provided by FullService Crime Laboratories ▯ Toxicology Unit o Examines body fluids and organs to determine the presence or absence of drugs and poisons Latent Fingerprint Unit o Processes and examines evidence for latent fingerprints when they are submitted in conjunction with other laboratory examinations Polygraph Unit o The polygraph or lie detector has come to be recognized as an essential look of the criminal investigator rather than the forensic scientist Voiceprint Analysis Unit o In cases involving telephoned threats or taperecorded messages, investigators may require the skills of the voiceprint analysis unit to tie the voice to a particular suspect CrimeScene Investigation Unit o This unit dispatches specially trained personnel to the crime scene to collect and preserve physical evidence that will later be processed at the crime laboratory ▯ ▯ Functions of the Forensic Scientist ▯ Analysis of Physical Evidence o The Importance of Physical Evidence Criminal cases are replete with examples of individuals who were incorrectly charged with and convicted of committing a crime because of faulty memories or lapses in judgment Errors may be compounded by misleading eyewitness statements and inappropriate confessions Scientific Method: A process that uses strict guidelines to ensure careful and systematic collection, organization, and analysis of information The underlying principles of the scientific method provide a safety net to ensure that the outcome of an investigation is not tainted by human emotion or compromised by distorting, belittling, or ignoring contrary evidence It begins by formulating a question worthy of investigation, such as who committed a particular crime. The investigator next formulates a hypothesis, a reasonable explanation proposed to answer the question. What follows is the basic foundation of scientific inquirythe testing of the hypothesis through experimentation The testing process must be thorough and recognized by other scientists as valid o Judging Scientific Evidence What the Court advocates in Daubert is that trial judges assume the ultimate responsibility for acting as a “gatekeeper” in judging the admissibility and reliability of scientific evidence presented in their courts o Providing Expert Testimony Generally, if a witness can establish to the satisfaction of a trial judge that he or she possesses a particular skill or has knowledge in a trade or profession that will aide the court in determining the truth of the matter at issue, that individual will be accepted as an expert witness ▯ ▯ Other Forensic Science Services ▯ Forensic Psychiatry o Forensic psychiatry is a specialized area in which the relationship between human behavior and legal proceedings is examined For civil cases, forensic psychiatrists normally determine whether people are competent to make decisions about preparing wills, settling property, or refusing medical treatment For criminal cases, they evaluate behavioral disorders and determine whether people are competent to stand trial o They also examine behavioral patterns of criminals as an aid in developing a suspect’s behavioral profile Forensic Odontology o Help identify victims when the body is left in an unrecognizable state o The characteristics of teeth, their alignment, and the overall structure of the mouth provide individual evidence for identifying a specific person o Another application of forensic odontology to criminal investigations is bite mark analysis A forensic odontologist can compare the marks left on a victim and the tooth structure of the suspect Forensic Engineering o Are concerned with failure analysis, accident reconstruction, and causes and origins of fires or explosions Forensic Computer and Digital Analysis o Law enforcement aspects of this work normally involve the recovery of deleted or overwritten data from a computer’s hard drive and the tracking of hacking activities within a compromised system ▯ ▯ ▯ ▯ Processing the Crime Scene ▯ Physical Evidence: Any object that can establish that a crime has or has not been committed or can link a crime and it’s victim to the perpetrator o Physical Evidence can achieve its optimum value in criminal investigation only when it’s collection is performed with a selectivity governed by the collector’s thorough knowledge of the crime laboratory’s techniques, capabilities, and limitations Securing and Isolating the Crime Scene o First priority should be given to obtaining medical assistance for individuals in need of it and to arresting the perpetrator o Also, extensive efforts must be put forth towards excluding all unauthorized personnel from the scene o The boundaries should encompass the center of the scene where the crime occurred, any paths of entry or exit, and any areas where evidence may have been discarded or moved o Efforts must be taken to identify all individuals at the scene and detain all potential suspects or witnesses still at the scene o To exercise proper control over the crime scene, the officer responsible for protecting it must have the authority to exclude everyone, including fellow police officers not directly involved in processing the site or in conducting investigation o Securing and isolating the crime scene are critical steps in an investigation, accomplishment of which is the mark of a trained and professional crimescene investigation team Recording the Crime Scene o Investigators have only a limited amount of time to work a crime site in its untouched state. The opportunity to permanently record the scene in its original state must not be lost o Such records not only will prove useful during the subsequent investigation, but are also required for presentation at a trial in order to document the condition of the crime site and to delineate the location of physical evidence o Notes, photography, and sketches are the three methods of crime scene recording o Notes Notetaker should start by identifying the person who contacted the investigator, the time of the contact and any preliminary information disclosed, including the case number. It is important to record the tasks assigned to each member of a team, as well as the beginning and ending times for the processing of the scene o Photography The most important prerequisite for photographing a crime scene is for it to be unaltered. Objects must not be moved until they have been photographed from all necessary angles If objects are removed, positions changed, or items added, the photographs may not be admissible as evidence at trial, and their intended value will be lost Crimescene photographs have great value in their ability to show the layout of the scene the position of evidence to be collected, and the relation of objects at the scene to one another Photographs are taken from many angles that can show possible lines of sight of victims, suspects, or witnesses. o Photographic Procedures At minimum four photographs are required at the crime scene: an overview photograph, a mediumrange photograph, a closeup photograph, and a closeup photograph with a scale o Video Recording Video recording is becoming very popular amongst the crime scene with their decrease in cost As with conventional photography, digital video should include the entire scene and the immediate surrounding areas Long shots as well as closeups should be taken in a slow and systematic manner There are however some disadvantages of using video recorders those being: Instability. Most cameras will inevitably shake during filming. Zooming and panning can be sloppy Extra noise due to wind or other investigators talking can obscure narration or may be inappropriate and damaging Because of this most mute the video and narrate separately while presenting Sketches If done correctly a sketch can clearly show the layout of an indoor or outdoor crime scene and the relationship in space of all the items and features significant to the investigation They are especially important to illustrate the location of collected evidence A rough sketch: A draft representation of all essential information and measurements at a crime scene. ▯ A finished sketch: A precise rendering of the crime scene, usually drawn to scale o Conducting a Systematic Search for Evidence o For a factual, unbiased reconstruction of the crime, the investigator, relying on his or her training and experience, must not overlook any pertinent evidence o Even when suspects are immediately seized and the motives and circumstances of the crime are readily apparent, a thorough search for physical evidence must be conducted at once. Failure in this, even though it may seem unnecessary, can lead to accusations of negligence or charges that the investigative agency knowingly “covered up” evidence that would be detrimental to its case Search Patterns o How one conducts a crimescene search will depend on the locale and size of the area, as well as on the actions of the suspect(s) and victim(s) at the scene Different search patterns: Strip or line search This method is best used in scenes where the boundaries are well established, because the boundaries dictate the beginning and end of the search lines Grid search This method is very thorough, but the boundaries must be well established in order to use this method as well Spiral search method Is helpful because the searcher is moving from an area light with evidence to an area where more evidence will most likely be found The searcher can easily locate footprints leading away from the scene in any direction Wheel/Ray search This method is not preferred because the areas between the “rays” are not searched Quadrant or zone search Best suited for scenes that cover large areas Locating Physical Evidence o Ultimately the investigator must rely on experience gained from numerous investigations to form a successful strategy for recovering relevant physical evidence o For example in homicide cases the search will center on the weapon and any evidence left as a result of contact between the victim and the assailant The crosstransfer of evidence, such as hairs, fibers, and blood, between individuals involved in the crime is particularly useful for linking suspects to the crime Collecting Physical Evidence o Clothing items should be handled carefully and wrapped separately to avoid loss of trace materials o Critical areas of the crime scene should be vacuumed and the sweepings submitted to the laboratory for analysis o The search for physical evidence must extend beyond the crime scene to the autopsy room of a decease victim Here the medical examiner or coroner carefully examines the victim to establish a cause and manner of death Handling Evidence o Investigators must handle and process physical evidence in a way that prevents any change from taking place between the time the evidence is removed from the crime scene and the time it is received by the crime laboratory Changes can arise through contamination, breakage, evaporation, accidental scratching or bending, or improper or careless packaging The use of gloves or forceps can help reduce this problem o Evidence should remain unmoved until investigators have documented its location and appearance in notes, sketches, and photographs Packaging Evidence o Forceps and similar tools may be used to pick up small items o Unbreakable plastic pill bottles with pressure lids are excellent containers for hairs, glass, fibers, and various other kinds of small or trace evidence o Charred debris recovered from a scene of a suspicious fire must be sealed in an airtight container to prevent the evaporation of volatile petroleum residues o Small amounts of trace evidence can be conveniently packaged in a carefully folded paper, using what is known as a “druggist fold” Biological Materials o If biological materials such as blood are stored in airtight containers, the accumulation of moisture may encourage the growth of mold, which can destroy their evidential value DNA Evidence o This technique is valuable for making it possible to identify suspects through detecting and analyzing minute quantities of DNA deposited on evidence as a result of contact with saliva, sweat, or skin cells o The search for DNA evidence should include any and all objects with which the suspect or victim may have come into bodily contact o One key concern during the collection of a DNAcontaining specimen is contamination, contamination in this case (introducing foreign DNA) can occur from coughing or sneezing onto evidence during the collection process Maintaining the Chain of Custody o Chain of Custody: A list of all people who came into possession of an item of evidence Refers to the chronological documentation or “paper trail” showing the seizure, custody, control, transfer, analysis, and disposition of physical or electronic evidence o Continuity of possession, or the chain of custody, must be established whenever evidence is presented in court as an exhibit o Adherence to standard procedures in recording the location of evidence, marking it for identification, and properly completing evidence submission forms for laboratory analysis is the best guarantee that the evidence will withstand inquiries of what happened to it from the time of its finding to its presentation in court o All items of physical evidence should be carefully packaged and marked upon their retrieval at crime sites This should be done with the utmost care to avoid destroying their evidential value or restricting the number and kind of examinations to which the criminalist may subject them Obtaining Standard/Reference Samples o The examination of evidence, whether soil, blood, glass, hair, fibers, and so on, often requires comparison with a known standard/reference sample o A standard/reference sample is: physical evidence whose origin is known, such as fibers or hair from a suspect, that can be compared to crimescene evidence o Buccal Swab: a swab of the inner portion of the cheek; cheek cells are usually collected to determine the DNA profile of an individual o Some types of evidence must also be accompanied by the collection of substrate controls Substrate controls: Uncontaminated surface material close to an area where physical evidence has been deposited. This sample is to be used to ensure that the surface on which a sample has been deposited does not interfere with laboratory tests Submitting Evidence to the Laboratory o Evidence is usually submitted to the laboratory either by personal delivery or by mail shipment The method is usually determined by the distance Most prefer to be shipped by mail However, postal regulations restrict the shipment of certain chemicals and live ammunition and prohibit the mailing of explosives Ensuring CrimeScene Safety o The increasing spread of HIV and AIDS has sensitized the law enforcement community to the potential health hazards at crime scenes The presence of blood and semen at crime scenes presents the investigator with biological specimens of unknown origin; the investigator has no way of gauging what health hazards they may contain. Therefor, caution and pretension must be used at all times Legal Considerations at the Crime Scene o In police work, perhaps no experience is more exasperating or demoralizing than to see valuable evidence excluded from use against the accused because of legal considerations. o This situation most often arises from what is deemed as “unreasonable” search and seizure of evidence o Therefore, removal of any evidence from a person or from the scene of a crime must be done in conformity with the Fourth Amendment privileges: unreasonable search and seizure o Allowances have been made to justify a warrantless search, those being: The existence of emergency circumstances The need to prevent the immediate loss or destruction of evidence A search of a person and property within the immediate control of the person, provided it is made incident to a lawful arrest A search made by consent of the parties involved o Can look at the cases Mincey v. Arizona and Michigan v. Tyler for examples of when there are exceptions to the fourth amendment o The message from the Supreme Court is clear: when time and circumstances permit, obtain a search warrant before investigating and retrieving physical evidence at the crime scene ▯ ▯ The Enrique Camarena Case: ▯ On February 7, 1985, SA Camarena left the DEA office when witnesses observed him being forced into the rear seat of a light colored car He was later found murdered and the suspects were convicted based on the sheets Camarena was wrapped in and matching sheets inside the suspects home ▯ Common Types of Physical Evidence ▯ Blood, Semen, and Saliva o All suspected blood, semen, or saliva (liquid or dried, animal or human) present in a form to suggest a relation to the offense or the people involved in a crime Documents o Any handwriting and typewriting submitted so that authenticity or source can be determined Drugs o Any substance seized in violation of laws regulating the sale, manufacturing and distribution of drugs Explosives o Any device containing an explosive charge, as well as all objects removed from the scene of an explosion that are suspected to contain the residue of an explosive Fibers o Any natural or synthetic fiber whose transfer may be useful in establishing a relationship between objects or people Fingerprints o All prints of this nature, latent and visible Firearms and ammunition o Any firearm, as well as discharged or intact ammunition, suspected of being involved in a criminal offense Glass o Any glass particle or fragment that may have been transferred to a person or object involved in a crime Hair o Any animal or human hair presents that could link a person with a crime Impressions o Tire markings, shoe prints, depressions in soft soils, and all other forms of tracks Organs and physiological fluids o Body organs and fluids are submitted for toxicology to detect possible existent of drugs and poisons Paint o Any paint, liquid or dried, that may have been transferred from the surface of one object to another during the commission of a crime Petroleum Products o Any petroleum product removed from a suspect or recovered from a crime scene Plastic Bags o A disposable polyethylene bag such as a garbage bag may be evidential in a homicide or drug case Plastic, rubber, and other polymers o Remnants of these manufactured materials recovered at a crime scene may be linked to objects recovered in the possession of a suspect perpetrator Powder Residues o Any item suspected of containing firearm discharge residues Serial Numbers o This category includes all stolen property submitted to the laboratory for the restoration of erased identification numbers Soil and Material o All items containing soil or minerals that could link a person or objects to a particular location. Common examples are soil embedded in shoes and sale insulation found on garments Tool marks o This category includes any object suspected of containing the impression of another object that served as a tool in a crime Vehicle Lights o Examination of vehicle headlights and taillights is normally conducted to determine whether a light was on or off at the time of a crime Wood and other vegetative matter o Any fragments of wood, sawdust, shavings, or vegetative matter discovered on clothing, shoes, or tools that could link a person or object to a crime location ▯ ▯ The Significance of Physical Evidence ▯ Identification o The process of determining a substance’s physical or chemical identity. Drug analysis, species determination, and explosive residue analysis are typical examples of this undertaking in a forensic setting o The process of identification first requires the adoption of testing procedures that give characteristic results for specific standard materials o Once these test results have been established, they may permanently be recorded and used repeatedly to prove the identity of suspect materials o Second, identification requires that the number and types of tests needed to identify a substance be sufficient to exclude all other substances Comparison o The process of ascertaining whether two or more objects have a common origin o First, combinations of select properties are chosen from the suspect and the standard/reference specimen for comparison o Once the examination has been completed, the forensic scientist must draw a conclusion about the origins of the specimens Individual Characteristics o Properties of evidence that can be attributed to a common source with an extremely high degree of certainty Examples of this: Fingerprints, DNA, Tattoo/Scar markings and handwriting characteristics Class Characteristics o Properties of evidence that can be associated only with a group and never with a single source Examples of this: Blood o The Product Rule Multiplying together the frequencies of independently occurring genetic markers to obtain an overall frequency of occurrence for a genetic profile ▯ ▯ Assessing the Significance of Physical Evidence ▯ One of the current weaknesses of forensic science is the inability of the examiner to assign exact or even approximate probability values to the comparison of most class physical evidence People are often disappointed to learn that most items of physical evidence retrieved at crime scenes cannot be linked definitively to a single person or object Although investigators always try to uncover physical evidence with individual characteristics (such as fingerprints, tool marks, and bullets) the chances of finding class physical evidence are far greater ▯ ▯ Assessing the Value of Physical Evidence ▯ The value of class physical evidence lies in its ability to corroborate events with data in a manner that is, as nearly as possible, free of human error and bias Only objects that exhibit a significant amount of diversity in our environment are deemed appropriate for classification as physical evidence In the same way, when one is dealing with more than one type of class evidence, their collective presence may lead to an extremely high certainty that they originated from the same source o As the number of different objects linking an individual to a crime increases, the probability of involvement increases dramatically ▯ ▯ Cautions and Limitations in Dealing with Physical Evidence ▯ In further evaluating the contribution of physical evidence, one cannot overlook one important reality in the courtroom: the weight or significance accorded physical evidence is a determination left entirely to the trier of fact, usually a jury of laypeople Often physical evidence, whether individual or class, is accorded great weight during jury deliberations and becomes a primary factor in reinforcing or overcoming lingering doubts about guilt or innocence Physical evidence may also exclude or exonerate a person from suspicion ▯ ▯ Forensic Databases ▯ In a criminal investigation, the ultimate contribution a criminalist can make is to link a suspect to a crime through comparative analysis o This comparison defines the unique role of the criminalist in a criminal investigation o Of course a one-on-one comparison requires a suspect Little or nothing of evidential value can be accomplished if a crime-scene investigators acquire fingerprints, hairs, fibers, paint, blood, and semen without the ability to link these items to a suspect ▯ ▯ Fingerprint Databases ▯ The premier model of all forensic database systems is the Integrated Automated Fingerprint Identification System (IAFIS), a national fingerprint and criminal history system maintained by the FBI IAFIS contains fingerprint and access to corresponding criminal history information for nearly 75 million subjects (or 750 million finger print images), which are submitted voluntarily to the FBI by state, local and federal law enforcement agencies ▯ ▯ DNA Databases ▯ CODIS (Combined DNA Index System) enable federal, state and local crime laboratories to electronically exchange and compare DNA profiles, thereby linking crimes to each other and to convicted offenders. CODIS creates investigative leads from three indexes: the forensic, offender, and arrestee indices o Currently holds about 470,000 DNA profiles from unsolved crime-scene evidence o The offender index contains the profiles of more than 10 million convicted individuals Constitutional issues regarding the appropriateness of collecting DNA from arrestees not convicted of any crime, but who nevertheless were the subject of a CODIS search against DNA collected from unsolved crimes, was decided in the case of Maryland v. King o When officers make an arrest supported by probable cause to hold for a serious offense and bring the suspect to a station to be detained in custody, taking and analyzing a cheek swab of the arrestee’s DNA is, like fingerprinting and photographing, a legitimate police booking procedure that is reasonable under the Fourth Amendment Rapid DNA: o A process for developing DNA profiles from a Buccal swab in 90 minutes or less that are compatible with a CODIS search ▯ ▯ Other Databases ▯ The National Integrated Ballistics Information Network (NIBIN) maintained by the Bureau of Alcohol, Tobacco, Firearms, and Explosives allows firearms analysts to acquire, digitize, and compare markings made by a firearm on bullets and cartridge casings recovered from crime scenes The heart of the NIBIN is the Integrated Ballistic Identification System (IBIS), comprising a microscope and computer unit that can capture an image of a bullet or cartridge casing The International Forensic Automotive Paint Data Query (PDQ) database contains chemical and color information pertaining to original automotive paints o This database, developed and maintained by the Forensic Laboratory Services of the Royal Canadian Mounted Police (RCMP), contains information about make, model, year, and assembly plant on more than 13,000 vehicles with a library of more than 50,000 layers of paint o The PDQ database has found its greatest utility in the investigation of hit-and-runs by providing police with possible make, model, and year information to aid in the search for the unknown vehicle There is one exception: a commercially available computer retrieval system for comparing and identifying crime-scene shoe prints know as SICAR (Shoeprint Image Capture and Retrieval) o SICAR’s pattern-coding system enables an analyst to create a simple description of a shoe print by assigning by either a scanner or a digital camera. ▯ ▯ Case Files (Page 70 in book) ▯ Gerald Wallace o Was found savagely beaten to death in his home, detectives searched his ransacked house gathering all the evidence they could find, none of it led to the murderer. With no witnesses the case went cold for 16 years until a lone finger print was lifted from a cigarette pack found in Wallace’s house. Within seconds the print hit a match which ultimately led police to the murder The Center City Rapist o Troy Graves left Philadelphia in 1999 to join the Air Force, and than settled down with his wife in Colorado. A frenzied string of eight sexual assaults around the Colorado University campus set off a manhunt that ultimately resulted in the arrest of Graves. However, his DNA profile inextricably identified him as Philadelphia’s notorious “Center City rapist”. This assailant attacked four women in 1997 and brutally murdered Shannon Schieber. In 2002 Graves was returned to Phiadephia, where he was sented to life in prison without parole o NIBIN Links Handgun to Suspects o After a series of armed robberies in which suspects fired shots, the sheriff’s office of Boward County, Florida, entered the cartridge casings from the crime scenes into NIBIN. Through NIBIN, four of the armed robberies were linked to the same .40-caliber handgun. A short time later, sheriff’s deputies noticed suspicious activity around a local business, when they attempted to interview the suspects they fled in a vehicle. During this chase the victims tried to dispose of the gun, which was later retrieved after the arrests were made. Firearm examiners confirmed the link through examination of the original evidence Aztec Gold Metallic Hit and Run o A 53 year old man was walking his dog in the early morning when he was struck and killed by an unknown vehicle and later found lying in the road. There were no witnesses and no leads to the investigation when a gold metallic painted fragment was recovered from the scene and the victims clothing and was submitted to the Virginia Department of Forensic Science for analysis. The most discriminating aspect of this paint was the unusual-looking gold metallic topcoat color. A search of automotive repaint books yielded only one color that closely matched the paint recovered from the scene. The color, Aztec Gold Metallic, was determined to have been used only on 1997 Ford Mustangs. The results of the examination were relayed via telephone to the investigating detective, the detective quickly determined that only 11,000 1997 For Mustangs were produced in Aztec Gold Metallic, and only two of these vehicles were registered and had previously been stopped in the jurisdiction of the offense. 90 minutes after the information was relayed they found the suspects vehicle. ▯ ▯ Wayne Williams Case ▯ 1981 the city of Atlanta was gripped by a two-year killing spree that left more than twenty young black males strangled or otherwise asphyxiated The only clues left were fibers found on the clothing of the victims, two types were isolated: yellow-green nylon and violet acetate o The yellow-green fibers were very unusual, coarse with a trilobed cross-sectional appearance, of a kind associated with carpets or rugs Once fiber analysis hit the newspapers, the killer began dumping his victims in rivers o Now they were either completely or partially nude Police staking out the Chattahoochee River, the killers favorite dumping ground heard a loud splash and than spotted a station wagon owned by Wayne Williams, a chubby twenty-three-year-old black music promoter o He was questioned but allowed to leave Two days later the body of Nathaniel Carter was dragged from the river a mile downstream; in his hair was a single yellow-green carpet fiber The police obtained a search warrant for Williams’s house and car, and throughout his home, the floor was covered with yellow-green carpeting With little actual evidence to connect Williams with the Atlanta slayings, it became apparent that this case would be decided in the laboratory o Working with chemists from DuPont, FBI analysts passed the yellow-green fibers recovered from the victims through a spinneret, giving it distinguishable optical characteristics o The unique trilobed cross-section enabled them to determine that it had been manufactured by Wellman Inc., a Boston textile company o Due to each carpet manufacturer having its own dyes and weaving techniques, it was possible to track these fibers to the West Point Pepperell Corporation of Dalton, Georgia West Point Pepperall had manufactured a line of carpeting known as Luxaire, and one of the colors offered was English Olive, which both visually and chemically matched the carpeting found in Williams’s home Although Luxaire was manufactured from 1970-1975 its use of the particular fiber was only used for one twelve-month period between 1970-1971 Even though Williams was suspected of as many as twenty-eight murders, prosecutors felt their best chance of conviction rested with just two cases: Nathaniel Carter and Jimmy Ray Payne o A single fragment of rayon found on Payne’s shorts, had been matched to the carpeting in Wayne Williams’s 1970 Chevrolet station wagon But still the prosecution wasn’t satisfied, during trial they introduced into evidence a chart showing twelve other victims of the Atlanta child killer, on each body 3-6 fibers could be traced to either Williams’s home or automobile Williams’s was convicted and sentenced to two life terms, however campaigners insisted that Williams had been railroaded by a racist police force determined to pin the crimes on a black man, rather than investigate allegations of a reported Ku Klux Klan involvement An absence of publicity available evidence to support these claims was also blamed on the state ▯ Crime-Scene Reconstruction ▯ ▯ Principles of Crime-Scene Reconstruction ▯ Law enforcement personnel must take proper action to enhance all aspects of the crime-scene search so as to optimize the crime-scene reconstruction o First, and most important, is securing and protecting the crime scene. o Before processing the crime scene for physical evidence, the investigator should make a preliminary examination of the scene as it was left by the perpetrator The investigator’s experience and the presence or absence of physical evidence become critical factors in reconstructing a crime The investigator captures the nature of the scene as a whole by performing an initial walk-through of the crime scene and contemplating the events that took place By using the physical evidence that is available to the naked eye he/she can than hypothesize what events took place ▯ ▯ Personnel Involved in Reconstruction ▯ Often reconstruction requires the involvement of law enforcement personnel, a medical examiner, and/or a criminalist (the scientific examination of physical evidence for legal purposes) Medical Examiner: Examine the victim at a crime scene and determine whether the body has been moved after death by evaluating the livor distribution within the body Criminalist: a criminalist applies scientific methods and techniques to examine and analyze evidentiary items and testifies in court as to his or her findings. o The use of a laser beam to plot the approximate bullet path interjectory analysis can help determine the probable position of the shooter relative to that of the victim o Other skills a criminalist may bring to the scene are: determining the direction of impact of projectiles penetrating glass objects, locating gunshot residues deposited on the victim’s clothing for the purpose of estimating the distance of a shooter from a target, searching for primer residues deposited on the hands of a suspect shooter, and analyzing blood splatter Crime-scene reconstruction: Method used to support a likely sequence of events at a crime scene by the observation and evaluation of physical evidence and statements made by individuals involved with the incident o Although the evidence alone may not describe everything that happened, it can support or contradict accounts given by witnesses and/or suspects o Can also generate leads and confirm the reconstruction of a crime to a jury o The collection, documentation, and interpretation of physical evidence is the foundation of a reconstruction. ▯ ▯ General Features of Bloodstain Formation ▯ The information one is likely to uncover as a result of bloodstain pattern interpretation includes the following: o The direction from which blood originated o The angle at which a blood droplet struck a surface o The location or position of a victim at the time a bloody wound was inflicted o The movement of a bleeding individual at a crime scene o The minimum number of blows that struck a bleeding victim o The approximate location of an individual delivering blows that produced a bloodstain pattern ▯ ▯ Surface Texture ▯ Surface texture is of paramount importance in the interpretation of bloodstain patterns; comparisons between standards and unknowns are valid only when identical surfaces are used o In general, harder and nonporous surfaces (such as glass or smooth tile) result in less splatter o Rough surfaces (such as concrete floor or wood) usually result in irregularly shaped stains with serrated edges, possibly with satellite splatter Satellite splatter: Small drops of blood that are distributed around the perimeter of a drop of drops of blood and were produced as a result of the blood impacting the target ▯ ▯ Direction and Angle of Impact ▯ An investigator may discern the direction of travel of blood that struck an object by studying the stain’s shape o As the stain becomes more elliptical in shape, its direction becomes more discernible because the pointed end of a bloodstain faces its direction of travel o The distorted or disrupted edge of an elongated stain indicates the direction of travel of the blood drop o Satellite spatter around parent stains will have the pointed end facing against the direction of travel A drop deposited at an angle of impact of about 90 degrees (directly vertical to the surface) will be approximately circular in shape with no tail or buildup of blood o However, as the angle of impact deviates from 90 degree
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