The Mystery Begins… Unit One
Unit One • Lesson 1.1 Investigating the Scene • Lesson 1.2 DNA Analysis • Lesson 1.3 The Findings
1.1 Essential Questions • What can be done at a scene of a mysterious death to help reconstruct what happened? • How do the clues found at a scene of a mysterious death help investigators determine what might have occurred and help identify or exonerate potential suspects? • How do scientists design experiments to find the most accurate answer to the question they are asking? • How are bloodstain patterns left at a crime scene used to help investigators establish the events that took place during a crime?
1.1.1 A Mysterious Death… It was a hot, 92°F summer morning. The emergency call came in at 9:45 am. A man contacted the police to report that he was worried about his next door neighbor, a woman named Anna Garcia. He informed the police that he had spoken to Anna the previous morning when he saw her walking her dog around 6:30 am. He noted that she was wearing a sweater even though they were currently experiencing a heat wave. He decided to call the police this morning because Anna’s dog had been barking excitedly for the last two hours (which is extremely unusual in this normally quiet suburban neighborhood). He tried to call Anna on the telephone, but no one answered. Next he tried ringing her doorbell, but there was no answer. The 911 operator notified the local police and the emergency medical technicians (EMT). Both the police and the EMT arrived at the scene at 9:56 am. The front door had to be broken down. Upon entering the house, they found Anna lying face down in the entry hallway. It was a comfortable 73˚F inside the house. The EMT determined that Anna was dead. The police immediately notified your team of crime scene investigators as well as the medical examiner, both of whom were dispatched to the house. Has a crime been committed?The mystery begins! It is your job to put together as many pieces of information as you can find. (Don’t worry – the dog was taken to the home of close family friends and is doing just fine.)
1.1.1 Course Materials Organization • Three Ring Binder- tabs for each unit, protocols and rubrics, career journals and for community service • Lab book- Notes on mini-lectures, experiments, activities and projects • Date • Name of lecture/activity • Name of partners/group • USB-Folders for each unit for all assignments within that unit
1.1.1 Processing a Crime Scene • New Program! • Very Cool! • Learn with a partner… While you work: Photos & Web Profiles!
1.1.2 Examining the Scene • Read the introduction • Get organized! • Search methods… • Examination • INVESTIGATE EVERY PART OF THE SCENE
1.1.2 Crime Scene Sketch Victim's Stats • Age: 38 • Weight: 165 • Height: 64 Inches • Race: Hispanic • Sex: Female
1.1.3 Career Journals • Persons of Interest
1.1.3 Career Journals • Documentation • End-of-text • In-text (later) • Validates our claims • Discuss later in detail • Decreases Plagiarism • No cut and paste • Grounds for dismissal
1.1.3 Career Journals • Career Journals • 911 Operator • EMT • Crime Scene Investigator • Guidelines • Rubric • Example • Wepage
1.1.4 The Evidence Work as a Forensic Scientist Process evidence to get answers and identify potential suspects! But… safety first.
1.1.4 Personal Protective Equipment (PPE) in Healthcare Settings • Specialized clothing or equipment worn by an employee for protection against infectious materials(OSHA) • Factors Influencing PPE Selection: • Type of exposure anticipated • Durability and appropriateness for the task • Fit • Gloves – protect hands • Gowns/aprons – protect skin and/or clothing • Masks and respirators– protect mouth/nose • Respirators – protect respiratory tract from airborne infectious agents • Goggles – protect eyes • Face shields – protect face, mouth, nose, and eyes
PPE for Standard Precautions Exposure 1 Exposure 2 Mask and goggles or a face shield – Use during patient care activities likely to generate splashes or sprays of blood, body fluids, secretions, or excretions • Gloves – Use when touching blood, body fluids, secretions, excretions, contaminated items; for touching mucus membranes and non-intact skin • Gowns – Use during procedures and patient care activities when contact of clothing/ exposed skin with blood/body fluids, secretions, or excretions is
Gloves: Most Important for US • Keep gloved hands away from face • Avoid touching or adjusting other PPE • Remove gloves if they become torn; perform hand hygiene before donning new gloves • Limit surfaces and items touched • Wash hands immediately after removing PPE. • Use soap and water or use an alcohol-based hand rub
Activity 1.1.4: Unknown Substance • Forensic Chemist • Presumptive tests • Type of substance • Confirmatory tests • Exact substance • Can we identify the unknown pills next to our victim?
Activity 1.1.4: Stations • Follow specific directions for how to perform the analysis at each station. • Fill out the Activity 1.1.4 Student Response Sheet as you work through each station. • Revise your theories of what happened to Anna. • Consider all analyzed evidence and what the evidence suggests at this time. • Include any updated theories or information to your Investigative Notes.
Activity 1.1.5 Experimental Design • Experiment- A research study conducted to determine the effect that one variable has upon another variable. • Researcher maximizes control over as many aspects of the environment as possible in order to prove that one variable affects another variable. • Reliable: • An experiment in which another researcher can perform exactly the same experiment and generate similar results. • Valid: • An experiment in which the results accurately describe the real world.
Holy GrailExperiments that are BOTH: • Reliable- Another researcher can perform exactly the same experiment and generate similar results. • Valid-Results accurately describe the real world.
Identify the Problem (question) • State the question you are trying to answer • Specific • Measurable • Example Problem: Does InstaGrow Fertilizer make plants grow larger than plants grown without InstaGrow Fertilizer?
Formulate a Hypothesis • The hypothesis is a clear prediction of the anticipated results. • If…then… • Indicates the independent and dependent variables in the experiment. • Independent Variable: varied or manipulated, presumed cause • Dependent Variable: measurable response, not manipulated, presumed effect
Independent Variables (IV) & Dependent Variables (DV) Does ___________ cause/affect ___________? Independent Variable Dependent Variable Example Problem: Does InstaGrow Fertilizer make plants grow larger than plants grown without InstaGrow Fertilizer? Does InstaGrow Fertilizer cause/affect plant growth? • Independent Variable: InstaGrow Fertilizer • Dependent Variable: Plant Growth
Example Hypothesis: • If fertilizer affects plant growth in a positive way then… The plants treated with InstaGrow Fertilizer will grow larger than the plants not treated with fertilizer. • IV: use of the fertilizer • DV: plant growth • The prediction of the results is clearly stated • The variables are clearly indicated
Design the Procedure • Step-by-step detail for how to perform the experiment • Every detail is important • Experiment must be replicable • All variables/conditions in an experiment need to be kept exactly the same (control variables) • Except the independent variable (IV) • Ensures that the IV is the only variable affecting the result
Control Group • Experiments need to include a control group • Independent variable being tested is not applied so that it may serve as a standard for comparison against the experimental group where the independent variable is applied. • Example: The control group for the fertilizer experiment is the group of plants NOT given the InstaGrow fertilizer.
Positive and Negative Controls Positive control Negative control Control groups where conditions produce a negative outcome Identify outside influences which may be present that were not accounted for • Group expected to have a positive result • Allows the researcher to show that the experimental set up was capable of producing results
The Importance of a Control Scientist #1: • The 10 plants grew an average of 40 inches each. Therefore, Scientist #1 concluded that InstaGrow Fertilizer makes plants grow larger. Scientist #2: • The 5 plants given InstaGrow Fertilizer grew an average of 39 inches each, while the 5 plants NOT given InstaGrow Fertilizer grew an average of 41 inches each. Therefore, Scientist #2 concluded that InstaGrow Fertilizer does NOT make plants grow larger. LARGER THAN WHAT????
The Importance of a Control Two scientists wanted to test to determine whether InstaGrowFertilizer makes plants grow larger. Scientist #2: • Ran the experiment with 10 plants. • Planted each plant in the same amount and type of soil. • Placed each plant in comparable environments. • Gave each plant the same amount of sun each day. • Gave each plant the same amount of water each day. • Gave 5 plants the same amount of InstaGrow Fertilizer, while 5 plants received no fertilizer. • Let grow for 30 days. Scientist #1: • Ran the experiment with 10 plants. • Planted each plant in the same amount and type of soil. • Placed each plant in comparable environments. • Gave each plant the same amount of sun each day. • Gave each plant the same amount of water each day. • Gave each plant the same amount of InstaGrow Fertilizer. • Let grow for 30 days.
Steps 4 & 5 • Carry out Procedure • Follow step-by-step procedure. • Collect the data in data tables. • Make and record observations. • Analyze data • Logically and clearly present all data and observations in the form of graphs and charts. • Clearly and concisely analyze all data and observations.
Draw Conclusions • Write a conclusion statement directly related to the original hypothesis • For example: “The hypothesis was correct…” • Explain the rationale for the conclusion and clarify any details. • Discuss any possible sources of error. • Anything that might have affected the results of the experiment.
Possible Next Steps • Change your hypothesis. • Re-design the procedure because of design flaws. • Develop new questions based on the work in this experiment. • Move on to a new or related research topic. • Why do some types of fertilizer work better than others…?
Time of Death • Why is it important (Brainstorm) • Temperature & Body Cooling • Partners & Assigned Temperatures:
Activity 1.1.5 Time of Death Approximate time of death: 11:00am– 4 hrs = 7:00am • How’d we do in determining Anna’s Time of Death? • List potential answers… • Glaister Equation: (98.4 – measured rectal temperature)/1.5 = approximate hours since death • The medical examiner measured Anna’s rectal temperature to be 92.4˚ at 11:00am. • = 4 hrs since death
Activity 1.1.6 Blood Splatter • Blood is powerful evidence! • What can blood can tell us? • What can blood splatter tell us?
Science Channel Video • http://science.discovery.com/tv-shows/science-channel-presents/videos/discoveries-this-week-blood-splatter.htm.
Activity 1.1.6 Blood Splatter • How can we determine if the blood at the crime scene was the result of an accident or foul play? • What role might height play? • Design an experiment to provide evidence for the case
Activity 1.1.6 Hints • Method produces different size drops • Dispersal (what pipette are you using?) • Collection (what are you dropping on to?) • Different drops are measurable • Don’t drop on the same spot • Test method • Use extreme heights (1cm vs. heighest measurement) • Measure with precision • Expect small but measurable differences!