Version 03 Sections Forensics. Science and Technology 11

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1 Version 03 Sections Science and Technology 11

2 Table of Contents Science and Technology 11 Course Overview 1 Section 1 An Introduction to 11 Lesson A: Forensic Specialties 13 Lesson B: Crime Scene Investigation Part I 15 Lesson C: Crime Scene Investigation Part II 23 Section 1 Assignment 31 Section 2 At the Lab 43 Lesson A: Estimating Time of Death 45 Lesson B: Examining Questioned Documents 51 Lesson C: Analyzing Chemical Substances 61 Lesson D: Analyzing Hair and Fibre Evidence 67 Section 2 Assignment 73 Section 3 Establishing Identities 97 Lesson A: Fingerprinting 99 Lesson B: DNA and Identity 105 Lesson C: Forensic Anthropology 111 Section 3 Assignment 119 Answer Key 143 Glossary 149 SCIENCE AND TECHNOLOGY 11

3 Course Overview Welcome to Science and Technology 11! Course Overview Have you ever wondered how a 400,000-kilogram plane can fly through the air? How scientists can help solve a murder by analyzing clues left at a crime scene? Or how devices such as the cell phone and the computer have transformed the way we communicate? In this course you will learn the answers to these and many other questions. You will develop an understanding of the connection between science and technology and how they can impact the environment and society. What s in this course? Science and Technology 11 consists of the following modules. Module 1: Natural Resources & the Environment Module 2: Personal Technologies Module 3: Transportation Module 4: Section 1: Major Resources of BC Section 1: An Introduction to Personal Technologies Section 1: An Introduction to Transportation Section 1: An Introduction to Section 2: Resource Extraction Section 2: The Evolution of Personal Technologies Section 2: A Closer Look at the Automobile Section 2: At the Lab Section 3: The Impact of Society on Resource Management Section 3: Personal Technologies within Systems Section 3: Transportation Systems Section 3: Establishing Identities Section 4: The Impact of Technologies on the Environment SCIENCE AND TECHNOLOGY 11 1

4 Section 1 Lesson B: Crime Scene Investigation Part I Lesson B Crime Scene Investigation Part I In this lesson, you will: describe the procedures for investigating a crime scene and gathering evidence. distinguish between different types of evidence. For this lesson, you will need: Science and Technology 11 Media CD Science and Technology 11 Website (optional): Crime Scene Investigation Procedures There are certain procedures that authorities attending a crime scene must follow. The first priority is preservation of life: if there is a victim who is severely injured, that person is helped immediately. The attending police officers then secure the crime scene. This means removing all unnecessary people from the area and creating a physical barrier so the general public cannot enter. Securing the crime scene prevents physical evidence from being contaminated (e.g., moved, removed, damaged, or altered). Contaminated evidence may ruin the case. An identification officer is then called in to the crime scene. An identification officer is specially trained to find, document, collect, and sometimes analyze, evidence that has been left behind. The identification officer is like the crime scene investigator you see on television. Meet the Forensic Specialist Jonathan Sheldan is an identification officer with the Victoria Police Department. As an identification officer, Jonathan performs four main duties. In this lesson you will learn what those duties are. SCIENCE AND TECHNOLOGY 11 15

5 Section 1 Lesson B: Crime Scene Investigation Part I Duty #1: Ensure the Crime Scene is Secure When Jonathan arrives at the crime scene, the first thing he does is make sure the area has been properly secured by the first attending police officers. Sometimes Jonathan will instruct these officers to widen or reduce the area that needs to be sealed off. No one can enter or leave this secure area unless Jonathan says so. Duty #2: Search the Crime Scene According to Locard s principle of exchange, a suspect always leaves physical evidence at a crime scene. Wherever he steps, whatever he touches, whatever he leaves, even unconsciously, will serve as a silent witness against him. Not only his fingerprints or his footprints, but his hair, the fibers from his clothes, the glass he breaks, the tool mark he leaves, the paint he scratches, the blood or semen he deposits or collects. All of these and more, bear mute witness against him. Professor Edmond Locard After the crime scene is properly secured, an identification officer like Jonathan does a thorough visual search for that evidence. Physical evidence may include things like tire tracks, gunshot residue, drugs, blood, or hair. Jonathan marks the location of each piece of evidence with a numbered card, like in the following photograph. 16 SCIENCE AND TECHNOLOGY 11

6 Section 1 Lesson B: Crime Scene Investigation Part I Activity 1 Crime Scene Investigation Procedures Organize the following crime scene procedures into the correct order. Put the number 1 beside the first event, 2 beside the second, and so on. a. b. c. d. e. f. g. Life-saving measures (if required) are employed. Photographs are taken of the crime scene. The crime scene is taped off. The police and other emergency personnel (first responders) are called to the crime scene. The area is searched for evidence. Evidence is collected and sent to the lab. Crime scene investigators (identification officers) are called to the scene. Go to the Answer Key at the end of this module to check your answers. More on Evidence As you ve learned, the goal of a criminal investigation is to find, collect, and analyze evidence from a crime scene in an effort to solve the crime. That evidence can be categorized as either circumstantial or direct. Circumstantial evidence suggests that someone is linked to the crime, but it doesn t prove he or she did it. Think back to the crime described at the beginning of this module: in that crime a bullet removed from the victim s body matched ones from her husband s gun. While this may suggest the husband shot her, it doesn t conclusively prove it. The evidence is circumstantial, because someone else may have fired the gun. SCIENCE AND TECHNOLOGY 11 19

7 Section 1 Assignment Your Name Student No. Section 1 Assignment: Part 2 Murder on Mayberry Street 1. Identify six procedural errors in the following scenario. (6 marks) An identification officer is called to the scene of a murder at 231 Mayberry Street. As he pulls up, he realizes it s the home of his daughter s best friend. The officer rushes in and goes to her body. He checks her pulse, but she s dead. She s lying on her side, so he turns her over to see if there s any evidence on her. He notices that she has been shot in the neck. The officer covers her with a blanket, then proceeds to look around the room. He finds a bullet casing, but doesn t touch it. As he bends down to look at it, he notices a gun lying under the dining room table. Carefully, he puts a pen in the muzzle and lifts it up, making sure that he doesn t touch the gun with his fingers. The officer returns the gun to its original position then sits down on the couch to wait for his boss, who will likely be in charge of the investigation. a. b. c. SCIENCE AND TECHNOLOGY 11 35

8 Section 2 Lesson A: Estimating Time of Death Lesson A Estimating Time of Death In this lesson, you will: describe methods used to estimate time of death. For this lesson, you will need: Science and Technology 11 Media CD Science and Technology 11 Website (optional): Sometimes there are witnesses who can state with certainty when a person died; other times there may be evidence such as a closed circuit video recording or a broken watch that can provide the same information. In the absence of direct evidence such as this, it is up to the coroner to estimate of time of death (T.O.D.). To do this, the coroner will consider the findings of experts such as identification officers, forensic pathologists and sometimes even forensic entomologists. In this lesson we will look at some of the methods used to estimate T.O.D. Body Temperature When a person is alive, each cell is hard at work, performing important functions for the body. The work of these cells is what ultimately creates our body heat. This heat is then moved throughout the body by the blood. One of the first things that happens after death is the body temperature drops until it equals that of the surrounding environment. This happens because the cells stop working and the blood stops moving. Theoretically, the body will cool at a constant rate per hour, and this can be used to estimate T.O.D. However, factors such as the room or outside temperature at T.O.D., the amount of clothing the victim is wearing, and the percentage of body fat on the victim can all affect the rate at which the body cools. Body temperature, then, will only provide a very rough estimate of T.O.D. It is important to supplement this estimate with other information. SCIENCE AND TECHNOLOGY 11 45

9 Section 2 Lesson A: Estimating Time of Death In 1991, a year-old mummy was found frozen in a glacier in Italy. He was so well preserved that forensic scientists were able to examine the contents of his stomach. They found that his last meal contained wheat, and that it had been eaten eight hours before he died. Insects Another method for estimating T.O.D. is to study the insects that appear on or near a body after death. Different species arrive at different times, depending on the body s stage of decomposition. Knowing this can help a forensic entomologist estimate when a person died. Meet the Forensic Specialist Dr. Gail Anderson is a forensic entomologist at Simon Fraser University in Vancouver, BC. She studies the insects on or near a body to help determine a person s time of death. Now go to your Science and Technology 11 Forensic Media CD. Click on Time of Death and watch the following short video clips with Dr. Anderson Blowfly Lifecycle and How Old is the Body? SCIENCE AND TECHNOLOGY 11 47

10 Section 2 Lesson A: Estimating Time of Death Once the body is no longer attractive to blowflies, other species of insects start colonizing the body. Like blowflies, when each species arrives and how long it stays is predictable and can help Gail estimate time of death. Activity 1 The Body as a Witness Temperature of Body Stiffness of Body Time Since Death Warm Not stiff Dead less than 3 hrs Warm Stiff Dead 3 8 hrs Cold Stiff Dead 8 36 hrs Cold Not Stiff Dead more than 36 hrs 1. A body is discovered at a crime scene. It is warm and stiff. Approximately how long has the victim been dead? a. b. c. d. 0 3 hours 3 8 hours 8 36 hours More than 36 hours 2. Livor mortis is fully visible in the victim. Does this match the time of death estimate? a. b. Yes. Full livor mortis sets in at least 6 8 hours after death. No. Full livor mortis sets in later than that. 3. Blood has pooled in the victim s feet and lower legs. This suggests the victim died: a. b. c. d. lying face down. in an upright position. on her back. on her side. SCIENCE AND TECHNOLOGY 11 49

11 Section 2 Lesson A: Estimating Time of Death 4. A second body is found in the woods nearby. The forensic entomologist finds 1st stage Eucalliphora latifrons on the body. The temperature is 23.3 C. Approximately how long has this second person been dead? a. b. c. d hours 42.5 hours 74 hours 78.2 hours Go to the Answer Key at the end of this module to check your answers. Lesson Summary Estimating time of death (T.O.D.) can be difficult. However, when taken together, factors such as body temperature, rigor mortis, livor mortis, stomach contents, and the presence of insects can help the coroner pinpoint T.O.D. with a reasonable degree of accuracy. Go to your Section 2 Assignment now and complete Part 2: Estimating Time of Death. 50 SCIENCE AND TECHNOLOGY 11

12 Section 2 Assignment Your Name Student No. 5. Compare each of these handwriting samples to the forged note from June 26th. Sandy s homework Leanne s homework Jessica s homework SCIENCE AND TECHNOLOGY 11 85

13 Section 3: Establishing Identities Section 3 Establishing Identities One of the challenges in ongoing investigations is identifying the people involved, such as the victim(s), suspect(s), or even the father in a paternity lawsuit. Numerous techniques are used to determine the identification of people. In the following lessons you will learn how latent fingerprints, DNA, and skeletal remains can be used to identify unknown subjects. SCIENCE AND TECHNOLOGY 11 97

14 Section 3 Lesson A: Fingerprinting Activity 1 Identifying Fingerprints Identify the correct class for each of these fingerprints. a. b. c. d. Go to the Answer Key at the end of this module to check your answers. Latent Fingerprint Detection Techniques Crime scenes are usually packed with fingerprints. Some of these are easy to see (like a bloody fingerprint on a doorknob), but others are not. Fingerprints that are completely invisible to the naked eye are called latent fingerprints. Finding these obviously takes more time than ones in plain view. There are many techniques for finding latent fingerprints. If the surface is non-porous, the identification officer will typically use a dusting powder. This powder collects on the moist areas of fingerprints, making them visible. Now go to your Science and Technology 11 CD. Click on Fingerprinting and watch Collecting Fingerprints. In this clip, Constable Jonathan Sheldan shows you how to retrieve fingerprints from a nonporous surface. 102 SCIENCE AND TECHNOLOGY 11

15 Section 3 Assignment Your Name Student No. Section 3 Assignment: Part 4 Doggone It! Lately, certain breeds of dogs have been crossed to produce offspring that carry desirable traits from both parents. The resulting puppies are quite valuable. You have decided to cash in on this, and bought yourself a Labrador female. You breed this female to a male Standard Poodle (the big ones) in hopes of producing some Labradoodles. You do this, but unfortunately, your dog gets out and mates with the neighbour s English Sheepdog. A few months later, your dog presents you with four puppies. However, you cannot be sure who their father is. Since a Labradoodle puppy is worth about 10 times as much as a Labrador Sheepdog cross, it is important that you establish who the real father is. To make things even more complicated, puppies from the same litter can have different fathers! Given below are the DNA profiles of the parent dogs and the four puppies. Compare the profiles of the puppies to each of the fathers then decide which dog was the father for each of the puppies. (4 marks = 1 mark for each correct answer) DNA Fingerprints of Parents Standard Poodle father A Labrador mother English Sheepdog father B DNA Fingerprints of Puppies Puppy #1 Puppy #2 Puppy #3 Puppy #4 SCIENCE AND TECHNOLOGY

16 Section 3 Lesson C: Forensic Anthropology Estimating Age Bone Fusion One way Brenda can estimate the age of a body is to look for evidence of bone fusion. When you re born, many of your bones are in separate pieces, like in Image A. As you get older, these pieces fuse together into a single bone, like in Image B. Image A: Femur (thigh bone) before bone fusion Image B Femur after bone fusion: The age of bone fusion in years: elbow 14 hands and feet 15 ankle 16 thigh (femur) 17 knee 18 wrist 19 shoulder 20 hip (ilium) 21 clavicle As you can see in Image C, each of your bones fuses at a different age. Knowing this can help Brenda estimate the age of the victim. If the elbow is fused, for example, the victim is likely at least 14 years old. However, if the wrist isn t fused, the victim is likely less than 19. Combining these two pieces of information, Brenda can estimate the victim s age more precisely in this case somewhere between years of age Bone fusion is a useful indicator of age for children, teenagers, and young adults. Once all of your bones are fused, however (about 28 years of age), it s much more difficult to estimate age. Image C: The approximate age of fusion for different bones in the human body 112 SCIENCE AND TECHNOLOGY 11

17 Section 3 Assignment Your Name Student No. Section 4 Assignment: Part 5 Old Bones Tell a Story Last summer, a construction company was called in to repair the foundation of a 90-year-old house. While removing the debris, the workers found some bones. Initially they thought that they were from an animal, but they soon realized that they had likely found human skeletal remains. A forensic specialist is called in to examine the bones. Here are some of the things she finds: The pelvis and sacrum are wide The skull is small with a rounded jaw The skull is 21 cm long There appears to be a healed fracture in the left humerus (upper arm) The end of the left femur has fused The clavicle has fused The rib bones are smooth and regular Meanwhile, an investigating officer goes through the Missing Person s reports from exactly 90 years ago (when the house was built). Since the bones were found under the foundation, it seems likely the person died at that time. Five people were reported missing that year and never found. Read each Missing Person Report carefully. SCIENCE AND TECHNOLOGY