1 / 22

Crime Scene Investigation UNIT

Physical evidence is the ultimate truth in crime investigations. Follow the dedicated members of the UNIT as they uncover the truth behind a mysterious murder. Will they find the real culprit?

hales
Télécharger la présentation

Crime Scene Investigation UNIT

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Crime Scene Investigation UNIT

  2. The Evidence Never Lies You can lead a jury to the truth but you can't make them believe it. Physical evidence cannot be intimidated. It does not forget. It doesn't get excited at the moment something is happening - like people do. It sits there and waits to be detected, preserved, evaluated, and explained. This is what physical evidence is all about. In the course of the trial, defense and prosecuting attorneys may lie, witnesses may lie, the defendant certainly may lie. Even the judge may lie. Only the evidence never lies. - Herbert Leon MacDonell (from Lewis, A. A. and MacDonell, H. L., (1984) The Evidence Never Lies: The Casebook of a Modern Sherlock Holmes, Dell Publishing, New York.)

  3. Don’t Overlook the Obvious Sherlock Holmes and Dr Watson went on a camping trip. After a good meal and a bottle of wine they lay down for the night, and went to sleep. Some hours later, Holmes awoke and nudged his faithful friend. "Watson, look up at the sky and tell me what you see." Watson replied, "I see millions and millions of stars." "What does that tell you?," enquired Holmes. Watson pondered for a minute. "Astronomically, it tells me that there are millions of galaxies and potentially billions of planets. Astrologically, I observe that Saturn is in Leo. Horologically, I deduce that the time is approximately a quarter past three. Theologically, I can see that God is all powerful and that we are small and insignificant. Meteorologically, I suspect that we will have a beautiful day tomorrow. What does it tell you?"

  4. Holmes was silent for a minute, then spoke. "Watson,you idiot! Someone has stolen our tent!"

  5. "The Bloody Desk" by Stan Smith The members of the Mervale crime scene unit were still busy in the office of David Travis that November evening when Sergeant Dan Connors came up to Inspector Susan Lieberman to report. "We haven't found the gun," he said. "Travis was shot at his desk from close range. He was a tax attorney, age 51. William Owens, age 53, who discovered the body, says he was a client of Travis's. He stopped by about quarter to eight this evening to ask Travis about an estate matter. Travis's outer office was dark, but the door was ajar and he saw a light under the inner door office. He says he knocked, pushed open the door, saw Travis slumped over his desk in a puddle of blood, and turned right around and ran to the lobby to call us from a pay phone." "He expected to find Travis in his office at quarter to eight?" asked Lieberman. "He says he knew Travis worked late hours." "Why didn't he call from the phone in the outer office?" "I asked him that. He said it never occurred to him; he just wanted to get out of there. His call came in at seven forty-eight. I was on patrol at the time and responded, arriving about eight. I accompanied Owens back to the inner office, flipped on the light, and found the body as he described."

  6. Lieberman and Connors stepped aside as the body of Travis was removed. "Who else in the building has been interviewed?" asked Lieberman. "There were only two others around. Kate Goggin, 47, is an accountant who works down the hall. Apparently they had an affair several months ago, but he abruptly ended it. She says she saw Travis in the hallway about quarter to seven, and they said hello. About seven-twenty and again about seven-forty, she heard a muffled bang, but assumed each time it was a truck backfiring. "The other person in the building," Connors continued, "was Russell Stetson, 32, the janitor. We discovered a record of petty theft but he says that was years ago and he's cleaned up his act. He says he emptied Goggin's trash about ten past seven. He didn't see her in her office at the time, but it looked like she had just stepped out. She says she was in the bathroom about that time. He emptied Travis's trash about seven-thirty, he reckons, and Travis was there alive and alone. He says he didn't hear the bangs Goggin referred to, but says he is partly deaf and was doing some vacuuming as well as collecting trash. About a quarter to eight, he went down to the lobby and saw Owens at the pay phone, though Owens did not notice him. Stetson proceeded to the basement to bag the trash. That's where we found him."

  7. "Interesting." Lieberman sighed and looked around the cluttered inner office. "There are offices on all three floors of this building, I suppose, and no security guard." "That's right." "Thank you, sergeant. The fingerprint report should be helpful, and I think I know whom it will implicate.“ Whom does Inspector Lieberman suspect? William OwensKate GogginRussell Stetson Why?

  8. The Solution Whom does Inspector Lieberman suspect? William Owens Why? If Owens were telling the truth, the sergeant would have found the inner office lit, since Owens had found it that way and had supposedly fled to phone the police without stepping into the inner office. When Connors arrived, however, he had to turn on the light. The first bang Goggin heard was indeed a truck backfiring. Owens murdered Travis when Travis threatened to blackmail Owens as a tax cheat. Owens switched off the light as he left the room but, realizing that a search of Travis's records might reveal him as a client and possibly a suspect, he decided to call the police and claim to have discovered the body, forgetting the inconsistency in his alibi. As Lieberman expected, his fingerprint (as well as those of Travis and Connors) was found on the light switch.

  9. Collecting Evidence Have you ever played the board game ClueTM? In this game, players gather information in order to determine the murderer, murder weapon, and crime scene. Actually, participants are not “guessing” when they play this game; they are using deductive reasoning. As players gather more information, they begin to put together the pieces of the mystery Police investigators follow a process similar to that used in ClueTM. The investigators collect and evaluate evidence from a crime scene. All of the information they gather is compiled and placed in the criminal case file. As new evidence becomes available, it is added to the file. Police investigators rarely learn about events in the same sequence in which they took place during the crime. Usually the leads are acquired in random order. Once a large portion of information is known, the police experts must sit down and put the pieces together, like you would assemble a jigsaw puzzle. Deductive reasoning is the thought process that police investigators use to assemble the pieces of the criminal puzzle and reach a logical conclusion. In deductive reasoning, investigators utilize logical and critical-thinking skills to reach a conclusion.

  10. ClueTM • We will work in groups of 2 to solve a ClueTM-likedeductive reasoning puzzle. • Fill out the chart to help you solve the case. Place an X when you can “rule out” something. Place a check mark when you know something for sure. Place a ? when it’s questionable. • You will need to match a victim (who’s gender you have identified) with a murderer, a crime scene, a weapon, and a TOD.

  11. Edmond Locard Edmond Locard was one of the most important figures in the history of forensic science. Locard worked as a medical examiner during World War I and was able to identify causes and locations of death by looking at stains or dirt left on soldier's uniforms, and in 1910, he opened the world's first crime investigation labin Lyons, France. Locard was somewhat of an Everyman, and he worked with great faith in analytical thought, objectivity, logic and scientific fact. Locard also wrote a highly influential seven-volume work on forensic science, titled "Traité de criminalistique," (Characteristics of a Criminal) and in it and his other works as a forensic scientist, he developed what would become known as Locard's exchange principle. In its simplest form, the principle is known by the phrase "with contact between two items, there will be an exchange." 

  12. Locard’s Exchange Principle Although Locard's Exchange Principle is generally understood as the phrase "with contact between two items, there will be an exchange," Edmond Locard never actually wrote down those words in the vast amount of material he produced, nor did he mention anything concerning a principle. Locard, however, did write the following: "It is impossible for a criminal to act, especially considering the intensity of a crime, without leaving traces of this presence."

  13. Locard, however, did write the following: "It is impossible for a criminal to act, especially considering the intensity of a crime, without leaving traces of this presence."

  14. Locard’s Beliefs • No matter where a criminal goes or what a criminal does, s/he will leave something at the scene of the crime. • A criminal can leave all sorts of evidence, including fingerprints, footprints, hair, skin, blood, bodily fluids, pieces of clothing and more. • S/he will also take something back with him/her. • By coming into contact with things at a crime scene, a criminal also takes part of that scene with him/her, whether it's dirt, hair or any other type of traceevidence.

  15. Interesting Facts… How many hairs does the average person shed per day? • Everyone loses between 40 & 120 strands a day, depending on how much hair you have, your age & your hair's growth cycle. People with fine hair tend to have more of it & therefore will lose more of it than their thicker-haired sisters & brothers. Your hair also thins as you get older, particularly after menopause for women, but the thinning will stop & not continue as it will for men.Here are common causes of hair loss:1. Seasonality. You'll lose the most hair in the fall -- typically November and December when hair reaches maturity in its growth cycle.2. Diet. 3. Pregnancy .4. Illness. Sometimes it happens as a result of illness. Even stress, excessive weight loss, iron deficiency & thyroid problems can cause hair loss.

  16. Interesting Facts… How many flakes of skin does the average person shed per minute? • Our skin weighs up to 4 kg and covers an area up to 1.3-1.7 sq m. getting dressed and undressed, rubbing body parts together, and even breathing cause microscopic flakes of skin to fall off at the rate of 50,000 flakes a minute. In a life time you will shed a total of 18kg of skin. Up to 80 percent of household dust is made of dead human skin cells.

  17. Locard “in action” • Dr. Locard tested out this principle during many of his investigations. In 1912, for instance, a Frenchwoman named Marie Latelle was found dead in her parents' home. Her boyfriend at the time, Emile Gourbin, was questioned by police, but he claimed he had been playing cards with some friends the night of the murder. After the friends were questioned, Gourbin appeared to be telling the truth. • When Locard looked at the corpse, however, he was led to believe otherwise. He first examined Latelle's body and found clear evidence that she was strangled to death. He then scraped underneath Gourbin's fingernails for skin cell samples and later viewed the results underneath a microscope. Very soon, Locard noticed a pink dust among the samples, which he figured to be ladies makeup. • Although makeup was popular around the time of the murder, it was by no means mass produced, and this was reason enough for Locard to search a little further. He eventually located a chemist who developed a custom powder for Latelle, and a match was made. Gourbin confessed the murder -- he had tricked his friends into believing his alibi by setting the clock in the game room ahead. Locard's exchange principle had worked.

  18. Observation • We’ve been talking a lot about observation skills and perception. • Now, let’s put some of those skills to use. • Look at the following crime scene and make some preliminary notes in your case book. • Make sure to include any questions that the evidence leads you to ask. • These will become your follow up questions with any witnesses to the crime. • Include an accurate sketch of the drawing in your case book. • There is no “answer”…I want to find out what you see and what you can infer from observing the scene.

  19. Crime Scene Photos from: Commons.wikimedia.org/wiki/File:Crime_scene.JPG and ci.lynnwood.wa.us

More Related