046325 Name_________________________________________________ Period_______________ Ms. Sameroff DO NOW OBJECTIVE: VOCABULARY ACTIVITY #1 ACTIVITY #2 Date______________ EXIT SWBAT summarize Locard’s exchange principle by completing a variety of activities. DO NOW 1. Which snake with arms are you today? Why? Read the following quote and answer the questions that follow. Paul L. Kirk in his 1953 book, Crime investigation: physical evidence and the police laboratory, explained Locard's theory of exchange: "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. This is evidence that does not forget. It is not confused by the excitement of the moment. It is not absent because human witnesses are. It is factual evidence. Physical evidence cannot be wrong, it cannot perjure itself, it cannot be wholly absent. Only human failure to find it, study and understand it, can diminish its value." 1. Explain the above quote using your own words. _______________________________________________________________________________________________________ _______________________________________________________________________________________________________ _______________________________________________________________________________________________________ _______________________________________________________________________________________________________ 2.Why is Locard's Principal significant to forensic science? _______________________________________________________________________________________________________ _______________________________________________________________________________________________________ _______________________________________________________________________________________________________ 3. Identify four types of evidence mentioned in the quote and state the unit that would be responsible for analyzing that evidence. _______________________________________________________________________________________________________ _______________________________________________________________________________________________________ _______________________________________________________________________________________________________ VOCABULARY (Use your notes to define the following words WORD PICTURE DEFINTION Locard’s Exchange Principle 1 Trace Evidence ACTIVITY #1 Use the bubble map below to come up with words you associate with trace evidence. After your done come to the board and share ONE of your responses with class. 2 1. Explain Locard’s Exchange Principle. _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ ______________________________ 2. In addition to the debris recovered from the suspect’s clothing, identify THREE other materials that may be transferred between individuals during a crime. _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ ______________________________ 3. A home burglary has occurred. It appears the perpetrator entered after breaking a window. A metal safe had been opened by drilling through its tumbler. A suspect was seen running through the garden. Three suspects were interrogated, and their clothing examined. List at least three examples of trace evidence that might be found on the suspect. ___________________________________________________________________________________________________ ___________________________________________________________________________________________________ ___________________________________________________________________________________________________ 4. Some examples of trace evidence are listed below. For each item, suggest a possible location where the trace evidence might have originated. For example, broken glass fragments-headlight from hit-and-run accident. 3 INSTRUCTIONS: Fill in the Blanks using the Wikipedia article below. Locard's exchange principle From Wikipedia, the free encyclopedia In forensic science, Locard's principle holds that the perpetrator of a crime will bring something into the crime scene and leave with something from it, and that both can be used as forensic evidence. Dr. Edmond Locard (1877–1966) was a pioneer in forensic science who became known as the Sherlock Holmes of Lyon, France.[1] He formulated the basic principle of forensic science as: "Every contact leaves a trace". It is generally understood as "with contact between two items, there will be an exchange." Paul L. Kirk[2] expressed the principle as follows: 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 fibres 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. This is evidence that does not forget. It is not confused by the excitement of the moment. It is not absent because human witnesses are. It is factual evidence. Physical evidence cannot be wrong, it cannot perjure itself, it cannot be wholly absent. Only human failure to find it, study and understand it, can diminish its value. 4 Fragmentary or trace evidence is any type of material left at (or taken from) a crime scene, or the result of contact between two surfaces, such as shoes and the floor covering or soil, or fibres from where someone sat on an upholstered chair. When a crime is committed, fragmentary (or trace) evidence needs to be collected from the scene. A team of specialised police technicians goes to the scene of the crime and seals it off. They record video and take photographs of the crime scene, victim/s (if there are any) and items of evidence. If necessary, they undertake ballistics examinations. They check for foot, shoe, and tire mark impressions, plus hair as well as examine any vehicles and check for fingerprints – whole or partial. 1. Edmund Locard was a pioneer of ____________ ______________ in France. 2. His exchange principle states that "Every ____________ leaves a __________. 3. Fragmentary or ____________ ________________ is any type of material left at—or taken from—a crime scene, or the result of ______________ between two surfaces. 4. When a crime is committed, ____________________ (or trace) evidence needs to be collected from the scene. ACTIVITY #2 Looking at Locard’s Exchange Principle in Action Recall: every contact you make with another person, place, or object results in an exchange of physical materials. Imagine you have 2 children and a cat. You run out to take care of some errands that include stopping at a furniture store, the laundromat, and the house of a friend who has one child and a dog. 1. What kinds of things might you leave behind? ________________________________________________________________________________________________ ________________________________________________________________________________________________ ________________________________________________________________________________________________ 2. What kinds of things might you pick up from each place? ________________________________________________________________________________________________ ________________________________________________________________________________________________ ________________________________________________________________________________________________ 3. If someone robbed your friend’s house that evening while your friend was away, they could place you at the scene of the crime. How could you defend yourself to the police? ________________________________________________________________________________________________ ________________________________________________________________________________________________ ________________________________________________________________________________________________ 5 EXIT TICKET 6 7 8 CASE STUDY 2: Madrid Bombings On 11 March 2004 a series of bombs devastated Madrid, Spain, k illing 191 people and wounding 2050. The bombings were widely assumed to be inspired by Al Qaeda but there appears to have bee n the involvement of several disparate groups and individuals. The trial of 28 accused ran from February to July 2007. At the end of October 2007, the Audiencia Nacional de España delivered its verdicts. Of the 28 defendants in the trial, 21 were found gui lty on a range of charges from forgery to murder. In the early stages of the investigation a blue plastic bag containing detonato rs was found near the scene of the bombings at a railway station. A print was taken from the bag and the FBI in the USA was se nt a digital copy of the print. An American lawyer Brandon Mayfield, who had converted to Islam, was identified by the FBI as a ma tch to the fingerprint. Mayfield was never charged with a crime but was arrested by the US authorities as a material witness w ith possible information about the Madrid bombing. Court records reveal the process that led to Mayfield's arrest in May 2004 an d his two-week detention in the Multnomah County Jail in Oregon, USA. According to the record, Mayfield's prints were among th e best 15 matches found by the FBI fingerprint computer, which holds the prints of some 45 million persons. Those matches were the n compared by FBI examiners to the digital image of the partial print sent by the Spanish authorities, who finding 15 matching characteristics concluded that the print was 'a 100 per cent identification' with Mayfield (Figure 3). Even as the FBI homed in on Mayfield, Spanish authorities were disputing the FBI's fingerprint analysis on the Madrid bag and the identification was not accepted in Spain. An independent fingerprint expert brought in by the FBI appeared, according to the court records, to confirm the FBI's attribution of the print to Mayfield. But Mayfield's lawyer said the expert's report had cautions that were not included in the FBI's affidavit (a sworn statement of evidence or fact that can be used in court without the author necessarily being present). Although not included in the FBI's affidavit the expert's report included concerns that the quality of the print copy that was received from Spain was poor and that the image possibly included an overlay of another print. The expert said that it was important to see the original image to make a definitive identification. It was soon recognized that an error had been made and Mayfield was released. The US attorney said the error was regrettable but that as soon as the misidentification came to light, federal authorities 'moved immediately' to have Mayfield released. The US Inspector General's Office (an office within the Department of Justice that can investigate waste, fraud and abuse within the US justice system) released a 273-page report in 2006 on the Mayfield affair. The report acknowledges that there was an 'unusual similarity' between the fingerprints, confusi ng three FBI examiners and a court-appointed expert. But the report also concluded that FBI examiners failed to adhere to the bure au's own rules for identifying latent fingerprints and that the FBI's 'overconfidence' in its own skills prevented it from tak ing the Spanish police seriously. known print from Mayfield known print from prime suspect Case Study 2 Questions 1. From the Madrid Bombings, Case Study 2, what is the pattern of Mayfield’s print? ______________ What is the pattern of prime suspect’s print? ________________ 9 2. How are both prints similar? 3. On the pictures above find, circle and label with type of minutiae 4 similarities between Mayfield’s and the Prime Suspects Prints 4. How are they different? 5. Summarize what happened to Mayfield. 6. How does this case change your views on fingerprinting? 10
