Forensic Science

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Outcomes: After studying this chapter you should be able to: * Define and distinguish forensic science and a nd criminalistics * Recognize the major contributors to the development of forensic science * Account for the rapid growth of forensic laboratories in the past forty years * Describe the services of a typical comprehensive crime laboratory in the criminal c riminal justice system * Compare and contrast the Frye and Daubert decisions relating to the admissibility of  scientific evidence in the courtroom * Explain the role and responsibilities of the expert witness * Understand what specialized forensic services, aside from the crime laboratory, are generally available to law enforcement personnel “Dr. Richard Saferstein's Criminalistics continues to be the gold standard of forensic science textbooks. He is simply unrivaled in his skill at making the crime lab exciting and accessible to all readers, ranging from forensic scientists and pathologists, to attorneys and judges, to law enforcement, to students and enthusiasts of all ages. I have, since the beginning of my career, relied upon various editions of Criminalistics, its accuracy, integrity and detail never failing  me. This compelling, latest updated edition of Criminalistics should be in every library and classroom, especially now in this era of proliferating forensic scientific advancements that make the impossible possible and mistakes unpardonable.” – Patricia Cornwell  Patricia Cornwell's recent bestsellers include Predator  include Predator , Trace Trace and  and Portrait  Portrait of a Killer: Jack the Ripper - Case Closed . Patricia Cornwell is Director of Applied Forensic Science at the National Forensic Academy. Visit her website at

1-1 Definition and Scope of Forensic Science  

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The word forensics word forensics means  means to verbally debate in public. Forensic science is the application of science to matters of law. It applies the knowledge and technology of science for the definition and enforcement of such laws. Each year science merges more closely with civil c ivil and criminal law as government deems it necessary to regulate re gulate activities which influence our daily lives. The Food & Drug Administration and Environmental Protection Agencies are examples of this. Criminal justice laws are continually being revised in response to increasing crime rates. Science does not offer absolute authoritative solutions, however it does supply accurate and objective information about what occurred at a crime scene. Forensic science is a very broad and comprehensive field of study. It is the application of science to those criminal  and civil laws that are enforced by police agencies in a criminal justice system. system. Forensic science and criminalistics are interchangeable terms. Criminalistics is a narrower term, indicating the services of a crime laboratory.

1-2 History & Development of Forensic Science 

The first “CSI” was Sir Arthur Conan Doyle’s (1859 - 1930) Sherlock Holmes series. This character popularized scientific crime-detection methods. Holmes applied blood-typing, fingerprinting, and other testing before they were  popular for real-life criminal investigations. Forensic science owes its origins to individuals such as Bertillon, Galton, Lattes, Goddard, Osborn, and Locard, who developed the principles and techniques needed to identify or compare physical evidence.



Where They Lived

Lived from/to

What They Did

W h en They Did It

Mathieu Orfila


1787 - 1853

“Father of Forensic Toxicology” - published the first scientific paper on detecting poison in animals.


Al Alph phon onse se Be Bert rtil illi lion on

Fr Fran ancce

1853 853 - 1914 1914

Devised the first scientific system of  personal  personal identification. Anthropometry is a systematic  procedure of taking a series of body measurements


Who They Are

as a means of distinguishing individuals. Conducted the first definitive study of fingerprints and their classification. Published Finger Published Finger Prints. Prints.

Francis Galton


1822 - 1911

Hans Gross


1847 - 1915

Wrote the first paper describing the application of   scientific principles to the field of criminal investigation. Published Criminal Investigation. Investigation.


Edmond Locard


1877 - 1966

Incorporated Gross’ principles within a workable crime laboratory; became the founder and director of the Institute of Criminalistics at the University of  Lyons.


Albert S. Osborn

U. S .

1858 - 1946

Developed the fundamental principles of document



examination; published Questioned Documents. Documents.

Leone Lattes


1887 - 1954

Developed a procedure to determine blood type (serology) from dried bloodstains. (Karl Landsteiner  discovered blood groups in 1901.)


Calvin Goddard

U. S .

1891 - 1955

Used a comparison microscope to determine if a  particular gun fired a bullet.


Walter C. McCrone

U. S .

1916 - 2002

A preeminent microscopist who utilized microscopy and other analytical methodologies to examine evidence.


Locard believed that a cross-transfer of evidence occurred every time a criminal came in contact with an object or person. This is called Locard’s Exchange Principle. Locard’s successes served as the impetus for the formation of police laboratories in several countries during dur ing the post-World War I period. The oldest US forensic lab was created in 1923 in Los Angeles by August Vollmer, a police chief from Berkeley, California. California has an integrated forensic system, linking regional laboratories with satellite facilities.  National forensic science laboratories were organized in the US in 1932 when J. Edgar Hoover (director of the FBI) opened a national laboratory. Performing over 1 million examinations every year, the FBI Laboratory is the largest in the world, and offers forensic service to all law enforcement agencies in the U. S. Its accomplishments have have won it worldwid worldwidee recognition. Great Britain has a national system of six regional laboratories that are under the direction of the Home Office. -2-


1-3 The Organization of a Crime Laboratory 

Crime laboratory development in the United States has been characterized by rapid growth without national and regional planning and coordination. There are currently about 350 public crime laboratories operate at various levels of government—federal (national), state, county, and municipal (city). With a large diversity of crime laboratories nationwide, it is impossible to use a general model that describes all. Laboratory staff sizes range from 1 - 100 people, and the services offered can be diverse or specialized. There has been an unparalleled growth of crime laboratories in the last 35 years, due to three things: -- 1) Supreme Court decisions decisions in the 1960's 1960's that are responsible for police placing greater emphasis emphasis on scientifically evaluated evidence. The advent of “Miranda Rights” has eliminated confessions as routine investigative tools. -- 2) Crime laboratories are inundated inundated with drug and other evidence specimens due tto o accelerated drug abuse and increased crime rates. -- 3) The advent of DNA profiling. profiling. Crime laboratories have have had to increase staff and laboratory space. DNA  profiling has influenced how the general public perceives modern crime laboratories. There are a variety of independent crime laboratories in the United States that precludes (keeps from happening) a national system. There is no single agency that has unlimited jurisdiction. There are four major federal crime laboratories that have been created to assist in cases that extend beyond state and local jurisdictions. They offer their expertise to any local agency that requests it. -- 1) Th The Federal Bureau of Investigation (FBI) maintains the largest crime laboratory in the world. -- 2) Th The Drug Enforcement Administration (DEA) are responsible for analyzing drugs seized in violation of  laws. -- 3) Th The Bureau of Alcohol, Tobacco, Firearms, and Explosives (ATF) analyze alcoholic beverages, explosive devices, weapons, and related evidence. -- 4) Th The U.S. Postal Inspection Service is concerned with crimes relating to the postal service. Most states maintain crime laboratories to t o provide service to local and re regional gional agencies that don’t have their own laboratories. Alabama and several other states have ha ve a comprehensive statewide system of regional and satellite laboratories. la boratories.

“Forensic science services are provided from ten (10) laboratories located througho ut the state (Huntsville, Florence,  Bi rm ing ha m/ Ho ov er, Ja ck son vill e, Tu sc alo os a, Mo bi le, Mo nt go me ry, Au bu rn , D ot ha n, an d Ca lera) ler a).. T he Hu nt sv ille ,  Bi rm in ingh gh am /Hoo /H oo ver , M ob ile, an d Mo ntg om ery La bo ra rato torie rie s a re pr og ra mm ed as ful l se rvi ce or reg iona io na l la bo rato ra tories ries . The T he se  La bo ra tor ies form fo rm the ba ckb on e o f th e A DF S for en sic lab or orat at or oryy s yst em . T he five (5 (5)) ssat at elli te lab or at ori es prov pr ov ide prim pr im arily ar ily drug chem istry and crime scene investigati investigation on services (Florence, Tuscaloosa, Jacksonville, Auburn, an d Dothan ). Death  In ve stig ati on servic ser vic es are ar e p erf or orme me d i n Hu nt svi lle , M on tgo me ry, an d Mo bi le m ed ica l ex am iner in er fac iliti es. Im pli ed Co ns en t  (breath alcohol) services are centralized in Calera. Executive and d epartment-wide adm inistrat inistrative ive activit activities ies are performed at  headqu arters, iin n Aubu rn, as required by law.”  

Statewide systems are operated under a central facility and provide services to most areas of the state. Regional laboratories have greatly increased the accessibility a ccessibility of law enforcement agencies to a laboratory while minimizing duplication of services. Local crime laboratories provide services to county and municipal (city) agencies, and are financed by local government. These operate independently of the state crime laboratories. Most of the larger cities in the U.S. maintain their own crime laboratories. More than 100 countries around the world have created and maintain crime laboratories.

1-4 Services of the Crime Laboratory 

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Different crime laboratories have a variety of services due to local laws, the capabilities of the agency, and budget limitations. Many crime laboratories have been created solely for the purpose of processing drug evidence. A “full-service” crime laboratory would include the following:



• Physical Science Unit – Incorporates the principles of chemistry, physics, and geology to identify and compare  physical evidence. -- May be further divided divided into Drug Identification, Soil & Mineral Analysis, and Trace Evidence sections. • Biology Unit – Applies the knowledge of biological sciences in order to investigate blood samples, body fluids,  botanical samples, hair, and fiber samples. -- Includ Includes es DNA DNA profil profiling ing • Firearms Unit – Investigates discharged bullets, cartridge cases, shotgun shells, and ammunition. ammunition. -- Also includes includes comparison comparison of of tool marks, marks, tire treads, treads, and shoe prints. prints. • Document Examination Unit – Provides the skills needed for f or handwriting analysis and other questioned document issues. -- Also analyzes paper and ink, indentations, obliterations, erasures, and burned or charred documents.

• Photography Unit – Applies special photographic techniques for recording and examining physical evidence. -- Special techniques include include digital imaging, infrared & ultraviolet, ultraviolet, and X-ray X-ray photog photography. raphy. Some crime laboratories may offer the optional services of toxicology, fingerprint analysis, voiceprint analysis, evidence collection, and polygraph administration. • Toxicology Unit – Examines body fluids and organs for the presence of drugs and poisons. -- Also responsible for training Breathalyzer Breathalyzer operators as well as maintenance of the instruments. • Latent Fingerprint Unit – Processes and examines evidence for latent fingerprints. • Polygraph Unit – Conducts polygraph (lie detector) tests, administered by people trained in investigation and interrogation. • Voiceprint Analysis Unit – Attempts to tie a recorded voice to a particular suspect. -- An instr instrum ument ent calle called d a sound a sound spectrograph makes a visual graphic display called a voiceprint . • Evidence-Collection Unit – Dispatches specially trained personnel to the crime scene to collect and preserve  physical evidence.

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A laboratory’s specialized units must not impede coordination of services for the criminal investigator. Forensic investigations requires the implementation of skills from many individuals in many of the units a crime laboratory has to offer.

1-5 The Functions of the Forensic Scientist  

A forensic scientist must be skilled s killed in applying the principles and techniques of the physical and natural sciences to the analysis of the many types of evidence e vidence that may be recovered during a criminal investigation. Procedures and techniques used in the laboratory must not only rely on firm science, but must also be admissible in court. The Frye Frye v.  v. United States  States decision set guidelines for determining the admissibility of scientific evidence into the courtroom. To meet the Frye the Frye standard,  standard, the evidence in question must be “generally accepted” by the scientific community. Some courts don’t rely on general acceptance as an absolute prerequisite for acceptance of evidence. The Federal   Rules of Evidence, Rule 702, specifies that “(1) the testimony is based upon sufficient facts of data, (2) the testimony is the product of reliable principles and methods, and (3) the witness has applied the principles and methods reliably to the facts in the case.” However, in the 1993 case of Daubert  v. Merrell , the U.S. Supreme Court asserted that  v. Merrell Dow Pharmaceutical, Inc.  , the the Frye the  Frye standard  standard is not an absolute prerequisite to the admissibility of scientific evidence. -4-


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Trial judges were said to be ultimately responsible as “gatekeepers” for the admissibility and validity of scientific evidence presented in their courts, as well as all expert testimony. The Daubert The  Daubert Criteria • In Daubert , the Supreme Court offered offer ed some guidelines as to how a judge can gauge scientific evidence: -- 1) Whether the the scientific scientific technique technique or theory can can be (and has been) tested. tested. -- 2) Whether the technique technique or theory has been been subject to peer review and pu publicat blication. ion. -- 3) The technique’s technique’s potential potential rate rate of error. error. -- 4) Existence and maintenance maintenance of standards controlling the technique’s operation. -- 5) Whether the scientific theory or method has attracted widespread widespread acceptance within a relevant scientific community. In the Khumo Tire Co., Ltd. v. Carmichael case, the Court rules that the “gatekeeping” role of the judge applied to all expert testimony. Another case which emphasized that new and unique testing te sting procedures are admissible only if they are based on scientifically valid principals and techniques is the  the Coppolino Coppolino v.  v. State  State case. A forensic scientist may also provide expert court testimony. An expert witness is an individual whom the court determines possesses knowledge relevant to the trial that is not expected of the average person. Trial courts have broad discretion on accepting an individual as an expert witness for any particular subject, but must ultimately rely on the training and years of experience as a measurement of the knowledge and ability of the expert. The expert witness is called on to evaluate evaluate evidence based on specialized training and experience that the court lacks the expertise to do. The expert will then express an opinion as to the significance of the findings. These views are only the expert’s opinion and may or may not be accepted by the jury. It is impossible for any expert witness to render any view with absolute certainty. The competence of a crime lab and its staff is useless if the evidence isn’t properly recognized, collected, and   preserved at a crime scene. scene. The forensic laboratory staff must be able to influence the conduct of the crime-scene investigation. This is addressed by the formation of specialized evidence-collection technicians on 24-hour call. The training of a crime-scene c rime-scene investigator must include hands-on training with forensic scientists in addition to classroom lectures. Forensic scientists also participate in training law enforcement personnel in the proper recognition, collection, and  preservation of physical evidence.

 Appendix I beginning on Page 543 describes the proper collection collection and packaging of  common types of evidence. Bookmark this page!

1-6 Other Forensic Science Services 

A number of special forensic science services are available a vailable to the law enforcement community to augment the services of the crime laboratory. These services include forensic pathology, forensic anthropology, forensic entomology, forensic psychiatry, forensic odontology, computer science, and forensic engineering. • Forensic Pathology – Involves the investigation investigation of unnatural, unexplained, or violent deathsd -- Forensic pathologists in their role as medical medical examiners or coroners are charged with determining the cause of death. -- The forensic forensic patholog pathologist ist may may conduct conduct an autopsy, which is the medical dissection and examination of a body in order to determine cause of death. -- After a human body expires, expires, there there are several stages stages of decomposition decomposition:: 

Rigor Mortis results in the shortening of muscle tissue and the stiffening of body parts in the position at death. It occurs within the first 24 hours and disappears within 36 hours. A medical examiner, when -5-


 presented with a body in rogor mortis, can determine that the time since death has been between 24 and 36 hours. 

Livor Mortis results in the settling of blood in areas of the body closest to the ground. It begins immediately on death and continues up to 12 hours. A medical examiner can determine if a body has been moved after death.

Algor Mortis results in the loss of heat by a body. As a general rule, beginning about an hour after death, the body loses heat by 1 - 1.5 degrees Fahrenheit per hour until the body reaches the environmental temperature. A medical examiner, when presented with a body, will take the core temperature of the body.

A normal body temperature is around 98.6 F. If the deceased body has a temperature of around 85.0 F, the medical examiner can determine that the time since death was between 9 and 14 hours. 

Potassium levels in ocular fluid (vitreous humor in the eye) also can help to eestimate stimate the time since death. Cells within the eye release potassium at a certain rate, and samples are taken for analysis. Other factors, such as the amount of food in the stomach at autopsy can indicate the time period in which the death occurred.

• Forensic Anthropology – Is concerned primarily with the identification identific ation and examination of human skeletal remains. -- Skeletal remains are are resistant to rapid decomposition and provide many indiv individual idual characteristics. -- A forensic anthropologist anthropologist may also help to create facial reconstructions to aid in indentification. • Forensic Entomology – Is the study of insects and a nd their relation to a criminal investigation. -- Insect evidence evidence is commonly commonly used used to estimate the time time since death. -- The specific insects present in the body and the stage of development of fly larvae approximate how long the  body has been left exposed. -- Environmental influences, such such as geographical geographical location, climate, and weather conditions m must ust be taken into consideration. • Forensic Psychiatry – Is an area in which the relationship between human behavior and legal proceedings proceedings is examined. -- Forensic psychiatrists are invol involved ved in both civil civil and legal proceedings. proceedings. • Forensic Odontology – Involves using teeth to provide provide information about the identification of victims when a  body is left in an unrecognizable state. -- Tooth enamel resists decomposition, and outlasts even skeletal remains. The characteristics of teeth are specific to each individual and can be used for identification. -- A forensic odontol odontologist ogist also also investigat investigates es bite marks. marks. • Forensic Engineering – Is concerned with failure analysis, accident reconstruction, and causes and origins of  fires or explosions. • Forensic Computer Science – Involves the examination of computers and digital evidence.


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