Forensic Science Topic 1. student notes

Forensic Science Topic One: Introduction

INTRODUCTION What exactly is Forensic Science? Forensic science applies the knowledge and technology of science to define and enforce laws. The History of Forensics Mathieu Orfila (Spain) “Father of Forensic Science”(1787-1853) • Alphonse Bertillon (France) (1853-1914) • Developed the science of Anthropometry – a way of taking extensive body measurements to identify people. This technique of personal identification was considered extremely accurate for 2 decades and was eventually replaced by fingerprinting. Francis Galton (1822-1911) • . Leone Lattes (1887-1954) • Devised a technique to determine the blood group of a dried bloodstain and applied the technique to criminal investigations. (The ABO blood groups were discovered by a Dr. Karl Landsteiner in 1901) Calvin Goddard (1891-1955)

• . Albert S. Osborne (1858-1946) • Published a book “Questioned Documents”, and was responsible for the acceptance of documents as scientific evidence by courts. Modern document examiners still use his book as primary refernce. Walter C. McCrone (1916-2002) • . Hans Gross (1847-1915) • . Last but not least… Edmond Locard (1877-1966) • Established “Locard’s Exchange Principle” which state that, whenever 2 objects come in contact with each other, there will be an exchange of materials between the two. • . •In 1932, thanks to J. Edgar Hoover, the director of the FBI, launched a national lab that would offer forensic services to the entire country’s law enforcement agencies. •Today, the FBI laboratory is the largest and most reputable in the world. Basic Services of a Full-Service Crime Lab • •Biology Unit • •Document Examination •

Optional Services of a Full-Service Crime Lab • •Latent Fingerprint Unit • •Voiceprint Analysis Unit • Specialized Forensic Services These are provided by specialized individuals, and are not usually a part of a full-service crime lab. •Forensic Pathology • •Forensic Entomology • •Forensic Odontology • 1.Forensic Pathology Investigates sudden, unnatural, unexplained, or violent deaths. Questions a forensic pathologist must attempt to answer: • • What injuries are present? • • What caused the injuries? • http://www.pathguy.com/TimeDead.htm If a cause of death cannot be determined by external observation of the body, then an Autopsy is required. Autopsy (means to see for oneself) This a medical dissection of a body to determine cause of death. Causes of death can be classified as: • • Homicide • • • Undetermined

•The early stages of decomposition after death involve: –Rigor mortis:. –Livor mortis: Once the heart stops pumping, the blood tends to pool in the parts of the body closest to the ground due to gravity. The skin in these areas appear purplish. However, skin that was restricted by belts, etc. will not appear purplish. This can help determine if the body was moved after death. Livor mortis begins immediately after death and continues for up to 12 hours. –Algor mortis: this is the conditions where the body temperature cools and reaches the ambient or room temperature. The location, size of body, clothing, weather conditions, etc. all play a role in algor mortis. Pallor Mortis: (paleness of death) is a postmortem paleness which happens almost instantaneously (in the 15–120 minutes after the death) because of a lack of capillary circulation throughout the body. Paleness develops so rapidly after death that it has little to no use in determining the time of death. Other Autopsy Factors •Potassium levels in vitreous humor of eye: after death, cells of the inner eye release potassium into the ocular fluid called vitreous humor. Examining these levels help determine time of death. • 2. Forensic Anthropology Deals with identification and examination of human skeletal remains. Bones degrade at an incredibly slow rate. They can tell: • • Age • • Type of injury (cause of death?) Forensic anthropologists are often needed to identify victims of a mass disaster such as air crashes, 9/11 WTC disaster, bombings, etc.

Ways to tell male pelvis from female: spread of ilium: shape of hole in ischium: smaller and triangular in female vs. larger and rounded in male angle across pubic symphysis: pubic arch: less than 90° (acute angle) and more sharply angled in male, greater than 90° (obtuse angle) and more rounded in female inner diameter and distance between ischia: •Sometimes forensic anthropologists have to use Facial Reconstruction artists to help identify the remains. http://www.crimelibrary.com/criminal_mind/forensics/art/5.html

3. Forensic Entomology • . • After death, specific insects become inhabitants of the corpse in a specific sequence. Blowflies are usually the first to arrive. Knowing the life cycles and studying the maggots can help determine time of death. Ambient temperatures can play a role in insect life cycles, so it can be tricky to rely solely on this method. A Blowfly and its maggots 4. Forensic Psychiatry The relationship between human behavior and legal proceedings is examined. Forensic psychiatry can help determine: • • Suspect’s behavioral profile • Behavioral patterns of criminals (Profiling) Susan Smith 5. Forensic Odontology Using teeth to identify remains. Tooth enamel is the hardest substance in the body and usually the last to decompose. So teeth can be used (and old dental records such as X-rays and casts) to identify a body in an unrecognizable condition. Dental Impressions and Casts 6. Forensic Engineering • •http://americasunknownchild.net/Medical.html •www.crimelibrary.com THE END

Forensic Science Topic 1. student notes

by Bob Smullen

Accessibility

Categories

Upload Details

Usage Rights

Statistics

Forensic Science Topic 1. student notes Document Transcript