Introduction Chapter 1 Forensic Science o Broad Definition

Introduction Chapter 1

Forensic Science o Broad Definition - The application of science to law o Broad Application - applies the knowledge and technology of science for the definition and enforcement of laws

Forensic Science o Working Definition - the application of science to those criminal and civil laws that are enforced by police agencies in a criminal justice system. o Criminalistics - more descriptive term for the services of a crime lab. o Criminalist vs Forensic Scientist

Forensic Science History o Mathieu Orfila (1787 -1853) - father of forensic toxicology; published the first scientific treatise on the detection of poisons and their effects on animals.

Forensic Science History o Alphonse Bertillon (1853 -1914) devised the first scientific system of personal identification; developed the science of anthropometry which is the systematic procedure of taking a series of body measurements as a means of distinguishing one individual from another; father of criminal indentification

Forensic Science History o Francis Galton (1822 -1911) performed the first definitive study of fingerprints and developed a methodology of classifying them

Forensic Science History o Leone Lattes (1887 -1954) - devised a relatively simple procedure for determining the blood group of a dried bloodstain

Forensic Science History o Calvin Goddard (1891 -1955) - used the comparison microscope to examine bullets; his expertise established the microscope as the indispensable tool of the modern firearms examiner

Forensic Science History o Albert S. Osborn (1858 -1946) developed the fundamental principles of document examination that are responsible for the acceptance of documents as scientific evidence by the courts

Forensic Science History o Walter C. Mc. Crone (1916 -2002) - the world’s preeminent microscopist; tireless advocate for applying microscopy to analytical problems, especially forensic science cases

Forensic Science History o Hans Gross (1847 -1915) - wrote the first treatise describing the application of scientific disciplines to the field of criminal investigations; detailed the assistance that investigators could expect from the fields of microscopy, chemistry, physics, mineralogy, zoology, botany, anthropometry and fingerprinting

Forensic Science History o Edmond Locard (1877 -1966) demonstrated how the principles of Hans Gross could be incorporated within a workable crime laboratory; he also believed that when a criminal came in contact with an object or person, a cross-transfer of evidence occurred; Locard’s Exchange Principle

Organization of Crime Lab o 320 public crime a labs o 3 times as many as in 1966 o Labs are very diverse so there is no set model o Supreme Court decisions in 1960’s had large impact in increase in lab numbers o Technological advancements also impacted the lab numbers

Services of Crime Labs o Services offered vary widely between labs n Variations in local laws n different capabilities and functions of the organizations to which a laboratory is attached n budgetary and staffing limitations

Basic Services of Full-Service Labs o Physical Science Unit n applies principles and techniques of chemistry, physics, and geology to the identification and comparison of crimescene evidence n staffed by criminalists who have expertise in chemical tests and modern analytical instrumentation for the examination of items as diverse as drugs, glass, paint, explosives, and soil

Basic Services of Full-Service Labs o Biology Unit n identification and DNA profiling of dried blood-stains and other body fluids, the comparison of hair and fibers, and the identification and comparison of botanical materials such as wood and plants n staffed with biologists and biochemists

Basic Services of Full-Service Labs o Firearms Unit n examination of firearms, discharged bullets, cartridge cases, chotgun shells, and ammunition of all types; garments and other objects are also examed in order to detect firearm discharge residues and to approximate the distance from a target at which a weapon was fired n the same principles are applied to tool marks

Basic Services of Full-Service Labs o Document Examination Unit n handwriting and typewriting on questioned documents are examined to ascertain authenticity and or source n Paper and ink, as well as indented writings, obliterations, erasures, and burned or charred documents are also examined

Basic Services of Full-Service Labs o Photography Unit n a complete photographic laboratory is maintained to examine and record physical evidence n procedures may require the use of highly -specialized photographic techniques, such as digital imaging, infrared, ultraviolet, and X-ray photography to make invisible information visible to the naked eye n also aid in preparation of photographic exhibit’s for courtroom presentation

Technical Support o Optional Services by Full-Service Labs n Toxicology Unit examines body fluids and organs for the presence of drugs and poisons. n Latent Fingerprint Unit processes and examines evidence for latent fingerprints. n Polygraph Unit conducts polygraph or lie detector tests. n Voiceprint Analysis Unit attempts to tie a recorded voice to a particular suspect. n Evidence-Collection Unit dispatches specially trained personnel to the crime scene to collect and preserve physical evidence.

Skills of a Forensic Scientist o A forensic scientist must be skilled in applying the principles and techniques of the physical and natural sciences to the analysis of the many types of evidence that may be recovered during a criminal investigation. o A forensic scientist may also provide expert court testimony. o An expert witness is an individual whom the court determines possesses knowledge relevant to the trial that is not expected of the average person.

Skills of a Forensic Scientist o The expert witness is called on to evaluate evidence based on specialized training and experience that the court lacks the expertise to do. o The expert will then express an opinion as to the significance of the findings. o Forensic scientists also participate in training law enforcement personnel in the proper recognition, collection, and preservation of physical evidence.

The Frye Standard o The Frye v. United States decision set guidelines for determining the admissibility of scientific evidence into the courtroom. o To meet the Frye standard, the evidence in question must be “generally accepted” by the scientific community.

Frye Not Absolute o However, in the 1993 case of Daubert v. Merrell Dow Pharmaceutical, Inc. , the U. S. Supreme Court asserted that the Frye standard is not an absolute prerequisite to the admissibility of scientific evidence. o 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 Criteria o In Daubert, the Supreme Court offered some guidelines as to how a judge can gauge scientific evidence: 1) Whether the scientific technique or theory can be (and has been) tested. 2) Whether the technique or theory has been subject to peer review and publication. 3) The technique’s potential rate of error.

The Daubert Criteria 4) Existence and maintenance of standards controlling the technique’s operation. 5) Whether the scientific theory or method has attracted widespread acceptance within a relevant scientific community.

Special Forensic Science Services o A number of special forensic science services are available to the law enforcement community to augment the services of the crime laboratory. o These services include forensic pathology, forensic anthropology, forensic entomology, forensic psychiatry, forensic odontology, computer science, and forensic engineering.

Special Forensic Science Services o. Forensic Pathology involves the investigation of unnatural, unexplained, or violent deaths. n Forensic pathologists in their role as medical examiners or coroners are charged with determining cause of death. n The forensic pathologist may conduct an autopsy which is the medical dissection and examination of a body in order to determine the cause of death.

Special Forensic Science Services o After a human body expires there are several stages of death. n Rigor mortis results in the shortening of muscle tissue and the stiffening of body parts in the position at death (occurs within the first 24 hours and disappears within 36 hours). n Livor mortis results in the settling of blood in areas of the body closest to the ground (begins immediately on death and continues up to 12 hours). n Algor mortis results in the loss of heat by a body (a general rule, beginning about an hour after death, the body loses heat by 1 to 1 -1/2 degrees Fahrenheit per hour until the body reaches the environmental temperature).

Special Forensic Science Services o Forensic Anthropology is concerned primarily with the identification and examination of human skeletal remains. o Forensic Entomology is the study of insects and their relation to a criminal investigation, commonly used to estimate the time of death. o Forensic Psychiatry is an area in which the relationship between human behavior and legal proceedings is examined.

Special Forensic Science Services o Forensic Odontology involves using teeth to provide information about the identification of victims when a body is left in an unrecognizable state; also investigates bite marks. o Forensic Engineering is concerned with failure analysis, accident reconstruction, and causes and origins of fires or explosions. o Forensic Computer Science involves the examination of digital evidence.